diff --git a/apps/server/src/provider/CodexDeveloperInstructions.test.ts b/apps/server/src/provider/CodexDeveloperInstructions.test.ts
index 5f4a28e886b6a..5fc45a2a2d964 100644
--- a/apps/server/src/provider/CodexDeveloperInstructions.test.ts
+++ b/apps/server/src/provider/CodexDeveloperInstructions.test.ts
@@ -58,7 +58,9 @@ describe("Codex runtime context", () => {
 
 describe("Codex orchestration context", () => {
   it("routes subagents native first, delegate_task for the rest", () => {
-    const orchestration = Object.entries(buildCodexAdditionalContext({ model: "gpt-6.1-sol" }))
+    const orchestration = Object.entries(
+      buildCodexAdditionalContext({ model: "gpt-6.1-sol" }, false),
+    )
       .filter(([key]) => key.startsWith("t3_code_orchestration_"))
       .map(([, entry]) => entry.value)
       .join("\n");
@@ -73,6 +75,7 @@ describe("Codex orchestration context", () => {
       orchestration.includes("Every new delegate review or re-check is a new `delegate_task`"),
     );
     NodeAssert.ok(orchestration.includes("never a `t3_thread_send`"));
+    NodeAssert.ok(orchestration.includes("a skill they invoked"));
     NodeAssert.ok(!orchestration.includes("inheritedOptions"));
     NodeAssert.ok(!orchestration.includes("Prefer native"));
     // The ACP terminal fallback is ACP-only; Codex agents never need it.
diff --git a/apps/server/src/provider/agentContextBudget.json b/apps/server/src/provider/agentContextBudget.json
index 486c4314927ad..c1508cbe98a56 100644
--- a/apps/server/src/provider/agentContextBudget.json
+++ b/apps/server/src/provider/agentContextBudget.json
@@ -1,5 +1,5 @@
 {
-  "claudeSystemAppendBytes": 5597,
-  "codexAdditionalContextBytes": 7327,
+  "claudeSystemAppendBytes": 5720,
+  "codexAdditionalContextBytes": 7485,
   "mcpToolListJsonBytes": 48131
 }
diff --git a/evals/mcp-tool-use/cases/visual-preview.ndjson b/evals/mcp-tool-use/cases/visual-preview.ndjson
index edd66f26966e9..42a66188cb364 100644
--- a/evals/mcp-tool-use/cases/visual-preview.ndjson
+++ b/evals/mcp-tool-use/cases/visual-preview.ndjson
@@ -34,3 +34,4 @@
 {"id": "browser-status-reuses-existing-tab", "area": "visual-preview", "kind": "control", "privacy": "commit-safe", "pattern": "usable Browser tab needs no new tab", "experience": "An already paired, usable tab should be reused during verification.", "source": {"report": "Maintainer browser verification failure, 2026-11-03"}, "setup": {"role": "top", "context": "The UI fix is complete. The test server is healthy at http://localhost:5173 and its browser profile is already paired. The current tab can be automated.", "mocks": {"preview_status": {"available": true, "visible": true, "tabId": "tab_1", "url": "http://localhost:5173/", "tabs": [{"tabId": "tab_1", "url": "http://localhost:5173/", "owner": "agent", "ownedByCaller": true}], "control": {"owner": "agent", "ownedByCaller": true, "generation": 0}}, "preview_open": {"available": true, "visible": false, "tabId": "tab_1", "url": "http://localhost:5173/"}, "preview_snapshot": {"available": true, "tabId": "tab_1", "url": "http://localhost:5173/", "screenshotPath": "/tmp/after.png"}}, "priorTurns": [{"role": "user", "text": "Use the Browser panel to verify the UI fix and capture an after screenshot."}, {"role": "assistant", "toolCalls": [{"tool": "Bash", "input": {"command": "cat .agents/skills/test-t3-app/SKILL.md"}, "result": "", "resultFile": ".agents/skills/test-t3-app/SKILL.md"}]}, {"role": "assistant", "toolCalls": [{"tool": "preview_status", "input": {}, "result": {"available": true, "visible": true, "tabId": "tab_1", "url": "http://localhost:5173/", "tabs": [{"tabId": "tab_1", "url": "http://localhost:5173/", "owner": "agent", "ownedByCaller": true}], "control": {"owner": "agent", "ownedByCaller": true, "generation": 0}}}]}], "harness": "claude"}, "prompt": "", "expect": {"calls": [{"tool": "preview_snapshot"}], "callsMustNot": [{"tool": "preview_open", "args": {"reuseExistingTab": false}}]}, "maxSteps": 10, "notes": "Checks reuse of an existing usable tab. Screenshot saving is outside this control. Prior tool-result replay is validated on the Claude harness; Codex output wrapping needs separate validation."}
 {"id": "browser-resume-after-unavailable-status", "area": "visual-preview", "kind": "bad", "privacy": "commit-safe", "pattern": "closed Browser panel treated as unavailable automation", "experience": "The agent read test-t3-app, saw available false with no tab, and asked the user to open the panel instead of calling preview_open. Opening a tab succeeded on the next turn.", "source": {"report": "Maintainer browser verification failure, 2026-11-03; fresh skill read followed by unavailable status. Opus replay reproduces the stop on the old skill."}, "setup": {"role": "top", "context": "Repository instructions: Before web or desktop UI verification, read .agents/skills/test-t3-app/SKILL.md and follow it. If a skill causes you to stop or leave requested work unfinished, link the SKILL.md, quote the relevant instruction, and explain how it applies.", "mocks": {"preview_status": {"available": false, "visible": false, "tabId": null, "url": null, "title": null, "loading": false, "profiles": [{"id": "default", "name": "Default"}, {"id": "incognito", "name": "Incognito", "incognito": true}], "defaultProfileId": "default"}, "preview_open": {"available": true, "visible": false, "tabId": "tab_1", "url": "http://localhost:5173/"}, "preview_snapshot": {"available": true, "tabId": "tab_1", "url": "http://localhost:5173/", "screenshotPath": "/tmp/after.png"}}, "world": {"repo": "acme/app", "branch": "fix/permissions-popup", "status": "", "files": {"apps/web/src/components/ComposerContextPermissions.tsx": "export function ComposerContextPermissions() { return <PermissionsMenu side=\"top\" align=\"end\" />; }\n"}, "description": "The requested fix is already committed as a1b2c3d on fix/permissions-popup, ahead of main. It changes ComposerContextPermissions.tsx to open the permissions popup above its trigger. Dependencies are installed. No development server is running and no .t3 directory exists.", "commits": [{"sha": "a1b2c3d", "subject": "fix(web): open composer permissions above its button"}]}, "priorTurns": [{"role": "user", "text": "When I click Full access in the composer, open its permissions menu directly above that button."}, {"role": "assistant", "toolCalls": [{"tool": "Bash", "input": {"command": "git commit -am \"fix(web): open composer permissions above its button\""}, "result": "[fix/permissions-popup a1b2c3d] fix(web): open composer permissions above its button\n 1 file changed, 3 insertions(+), 1 deletion(-)"}]}, {"role": "assistant", "text": "Implemented. Clicking Full access opens the permissions menu above the button. Focused checks pass. Full-client visual verification remains undone."}, {"role": "user", "text": "before/after screenshot"}, {"role": "assistant", "toolCalls": [{"tool": "Bash", "input": {"command": "cat .agents/skills/test-t3-app/SKILL.md"}, "result": "", "resultFile": ".agents/skills/test-t3-app/SKILL.md"}]}, {"role": "assistant", "text": "I'll use the test-t3-app skill to capture the before and after states in the app."}, {"role": "assistant", "toolCalls": [{"tool": "preview_status", "input": {}, "result": {"available": false, "visible": false, "tabId": null, "url": null, "title": null, "loading": false, "profiles": [{"id": "default", "name": "Default"}, {"id": "incognito", "name": "Incognito", "incognito": true}], "defaultProfileId": "default"}}]}], "shellMocks": [{"match": "git status|ls .*\\.t3", "output": "ls: .t3: No such file or directory"}], "harness": "claude"}, "prompt": "", "expect": {"calls": [{"tool": "preview_open"}]}, "maxSteps": 8, "notes": "Resume at the failed decision after reading the skill and receiving available=false. Opus reproduces the premature stop; Sonnet did not reliably reproduce it. This checks recovery through preview_open, not completion of screenshots. Prior tool-result replay is validated on the Claude harness; Codex output wrapping needs separate validation."}
 {"id": "revise-page-resends-html", "area": "visual-preview", "kind": "bad", "pattern": "revising a page on disk resends its full HTML to html_preview and html_render", "experience": "The pages already existed as generated files on disk, but the agent retyped each one into html_preview and again into html_render, about four minutes per call. To save time it published fixes without previewing them again.", "source": {"discussion": "https://github.com/pingdotgg/t3code/discussions/23303"}, "rule": "edit the .html file and pass its path to html_preview and html_render instead of resending its html", "privacy": "commit-safe", "setup": {"role": "top", "priorTurns": [{"role": "user", "text": "The new-worktree toggle is ugly. Come up with four better options and mock them."}, {"role": "assistant", "text": "Here are four options.", "toolCalls": [{"tool": "Write", "input": {"file_path": "/tmp/design/index.html", "content": "<!doctype html><html><head><meta charset=\"utf-8\"><style>body{margin:0;font-family:var(--font-sans)}.opt{padding:16px;border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px}.composer{border:1px solid var(--border);border-radius:8px;padding:10px;color:var(--muted-foreground)}.row{display:flex;gap:8px;align-items:center;margin-top:8px}button{border:1px solid var(--border);border-radius:6px;padding:4px 10px;background:transparent;color:inherit}</style></head><body>\n<div class=\"opt\"><h3>A. Checkbox under the composer</h3><div class=\"composer\">Ask anything</div><label class=\"row\"><input type=\"checkbox\"> New worktree</label></div>\n<div class=\"opt\"><h3>B. Toggle in the toolbar</h3><div class=\"row\"><button>Model</button><button>Mode</button><button aria-pressed=\"true\">Worktree: on</button></div><div class=\"composer\">Ask anything</div></div>\n<div class=\"opt\"><h3>C. Split send button</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send</button><button>v</button><span>Send in new worktree</span></div></div>\n<div class=\"opt\"><h3>D. Two visible choices</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send here</button><button>Send in new worktree</button></div></div>\n</body></html>\n"}, "result": "File created successfully at: /tmp/design/index.html"}, {"tool": "html_preview", "input": {"html": "<!doctype html><html><head><meta charset=\"utf-8\"><style>body{margin:0;font-family:var(--font-sans)}.opt{padding:16px;border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px}.composer{border:1px solid var(--border);border-radius:8px;padding:10px;color:var(--muted-foreground)}.row{display:flex;gap:8px;align-items:center;margin-top:8px}button{border:1px solid var(--border);border-radius:6px;padding:4px 10px;background:transparent;color:inherit}</style></head><body>\n<div class=\"opt\"><h3>A. Checkbox under the composer</h3><div class=\"composer\">Ask anything</div><label class=\"row\"><input type=\"checkbox\"> New worktree</label></div>\n<div class=\"opt\"><h3>B. Toggle in the toolbar</h3><div class=\"row\"><button>Model</button><button>Mode</button><button aria-pressed=\"true\">Worktree: on</button></div><div class=\"composer\">Ask anything</div></div>\n<div class=\"opt\"><h3>C. Split send button</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send</button><button>v</button><span>Send in new worktree</span></div></div>\n<div class=\"opt\"><h3>D. Two visible choices</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send here</button><button>Send in new worktree</button></div></div>\n</body></html>\n"}, "result": "{\"width\":728,\"contentHeight\":1840,\"capturedHeight\":1840,\"consoleMessages\":[]}"}, {"tool": "html_render", "input": {"html": "<!doctype html><html><head><meta charset=\"utf-8\"><style>body{margin:0;font-family:var(--font-sans)}.opt{padding:16px;border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px}.composer{border:1px solid var(--border);border-radius:8px;padding:10px;color:var(--muted-foreground)}.row{display:flex;gap:8px;align-items:center;margin-top:8px}button{border:1px solid var(--border);border-radius:6px;padding:4px 10px;background:transparent;color:inherit}</style></head><body>\n<div class=\"opt\"><h3>A. Checkbox under the composer</h3><div class=\"composer\">Ask anything</div><label class=\"row\"><input type=\"checkbox\"> New worktree</label></div>\n<div class=\"opt\"><h3>B. Toggle in the toolbar</h3><div class=\"row\"><button>Model</button><button>Mode</button><button aria-pressed=\"true\">Worktree: on</button></div><div class=\"composer\">Ask anything</div></div>\n<div class=\"opt\"><h3>C. Split send button</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send</button><button>v</button><span>Send in new worktree</span></div></div>\n<div class=\"opt\"><h3>D. Two visible choices</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send here</button><button>Send in new worktree</button></div></div>\n</body></html>\n", "title": "New worktree: four options", "height": 1840}, "result": "{\"htmlRender\":{\"attachmentId\":\"att-1\",\"title\":\"New worktree: four options\",\"height\":1840},\"message\":\"Shown to the reader above your reply. Don't mention or describe the page; reply with only what it doesn't already say.\"}"}]}], "mocks": {"html_preview": {"width": 728, "contentHeight": 1840, "capturedHeight": 1840, "consoleMessages": []}, "html_render": {"htmlRender": {"attachmentId": "att-1", "title": "New worktree: four options", "height": 1840}, "message": "Shown to the reader above your reply. Don't mention or describe the page; reply with only what it doesn't already say."}}, "world": {"files": {"/tmp/design/index.html": "<!doctype html><html><head><meta charset=\"utf-8\"><style>body{margin:0;font-family:var(--font-sans)}.opt{padding:16px;border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px}.composer{border:1px solid var(--border);border-radius:8px;padding:10px;color:var(--muted-foreground)}.row{display:flex;gap:8px;align-items:center;margin-top:8px}button{border:1px solid var(--border);border-radius:6px;padding:4px 10px;background:transparent;color:inherit}</style></head><body>\n<div class=\"opt\"><h3>A. Checkbox under the composer</h3><div class=\"composer\">Ask anything</div><label class=\"row\"><input type=\"checkbox\"> New worktree</label></div>\n<div class=\"opt\"><h3>B. Toggle in the toolbar</h3><div class=\"row\"><button>Model</button><button>Mode</button><button aria-pressed=\"true\">Worktree: on</button></div><div class=\"composer\">Ask anything</div></div>\n<div class=\"opt\"><h3>C. Split send button</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send</button><button>v</button><span>Send in new worktree</span></div></div>\n<div class=\"opt\"><h3>D. Two visible choices</h3><div class=\"composer\">Ask anything</div><div class=\"row\"><button>Send here</button><button>Send in new worktree</button></div></div>\n</body></html>\n"}}}, "prompt": "Make the Send in new worktree button in option C blue, and show me the page again.", "expect": {"calls": [{"tool": "html_preview", "args": {"path": "/tmp/design/index.html", "html": null}}, {"tool": "html_render", "args": {"path": "/tmp/design/index.html", "html": null}}], "callsMustNot": [{"tool": "html_preview", "args": {"html": "~Ask anything"}}, {"tool": "html_render", "args": {"html": "~Ask anything"}}], "order": ["html_preview", "html_render"]}, "notes": "On main neither tool has a path parameter."}
+{"id": "invoked-skill-uses-separate-browser", "area": "visual-preview", "kind": "bad", "pattern": "an invoked skill names a separate signed-in browser but the agent insists on preview tools", "experience": "The user invoked a skill whose instructions named another browser. The agent refused to follow it because T3's orchestration text said preview tools only.", "rule": "Another browser named by an invoked skill: use it, not preview, and report any prerequisite it is missing.", "privacy": "commit-safe", "setup": {"role": "top", "context": "The user has invoked member-portal-browser. Its loaded SKILL.md instructions are: For the signed-in Acme member portal, use `portal-browser --session member read <url>`. This helper controls a separate browser with the user's existing sign-in. It opens the URL and returns the visible page text. The helper is installed, the member session is signed in, and no prerequisite is missing.", "shellMocks": [{"match": "portal-browser\\s+--session\\s+member\\s+read\\s+https://members\\.acme\\.example/announcements/latest", "output": "Latest announcement: Scheduled maintenance\nThe member portal will be unavailable on Friday from 02:00 to 03:00 UTC."}], "world": {"repo": "acme/app", "branch": "main", "status": "", "description": "portal-browser is installed and its member session is signed into https://members.acme.example. The read command uses that separate browser to return visible page text."}}, "prompt": "/member-portal-browser Read the latest announcement at https://members.acme.example/announcements/latest and tell me when the portal will be unavailable.", "expect": {"notCalls": ["preview_status", "preview_open", "preview_dialog", "preview_navigate", "preview_resize", "preview_set_appearance", "preview_snapshot", "preview_act", "preview_evaluate", "preview_wait_for", "preview_recording_start", "preview_recording_stop"], "shellMust": ["portal-browser\\s+--session\\s+member\\s+read\\s+https://members\\.acme\\.example/announcements/latest"], "finalTextMust": ["[Ff]riday", "02:00", "03:00"]}, "source": {"restoration": "https://github.com/pingdotgg/t3code/pull/16956", "regression": "https://github.com/pingdotgg/t3code/pull/24850"}, "notes": "Authored generic skill, site and helper. Uses the default browser-access state: Codex input hard-codes browser:true, so this case does not model browser access off. The required helper command and final announcement details prevent a refusal from passing.", "maxSteps": 8}
diff --git a/packages/provider-core/src/server/orchestrationInstructions.ts b/packages/provider-core/src/server/orchestrationInstructions.ts
index 9c9720edf18b7..ff1499c17c68b 100644
--- a/packages/provider-core/src/server/orchestrationInstructions.ts
+++ b/packages/provider-core/src/server/orchestrationInstructions.ts
@@ -21,7 +21,7 @@ Ordinary coding tasks need no T3 tools.
   `### Visuals and preview
 
 - Answer data with a trend or comparison with a chart, and show any visual the user asks for here: pass the path to an HTML file, or inline HTML to \`html_preview\`, then \`html_render\`. A screenshot on disk or a text description does not show it. Never start a server for it. Page tools write only on user request. Never use them to show results. Asked for an image to post, send, or use elsewhere: a \`.png\` file and its path, never \`html_render\`.
-- Never use \`preview_*\` unasked to verify or show your own edit. Use them when the current request asks for browser work, including recording edits, or names a page or tab. Do not repeat preview calls from an earlier turn. Public pages: web fetch or search unless browser work was asked; then preview tools only, no web fetch. Close a tab you opened before you reply, unless the user asked for it or uses it.`,
+- Never use \`preview_*\` unasked to verify or show your own edit. Use them when the current request asks for browser work, including recording edits, or names a page or tab. Do not repeat preview calls from an earlier turn. Public pages: web fetch or search unless browser work was asked; then preview tools only, no web fetch. Another browser named by the user or a skill they invoked: use it, not preview, and report any prerequisite it is missing. Close a tab you opened before you reply, unless the user asked for it or uses it.`,
 ];
 
 export const T3_CODE_ORCHESTRATION_INSTRUCTIONS = `
@@ -33,7 +33,7 @@ export const T3_CODE_BROWSER_TOOL_INSTRUCTIONS = `
 
 ## T3 Code browser
 
-When browser work was asked, \`preview_*\` is the browser you share with the user: \`preview_status\` first, then \`preview_open\` if no tab can be automated. Prefer snapshot locators over coordinates. Switch browsers only if the tools are absent or \`preview_open\` says unsupported, the user asks, or two preview calls fail on one step. Then quote the error and switch.
+When browser work was asked, \`preview_*\` is the browser you share with the user: \`preview_status\` first, then \`preview_open\` if no tab can be automated. Prefer snapshot locators over coordinates. Switch browsers only if: the tools are absent or \`preview_open\` says unsupported; the user or an invoked skill names another browser; or two preview calls fail on one step. Quote any error, then switch.
 `;
 
 const T3_CODE_DEVICE_TOOLS = ["device_list", "device_open", "device_screenshot", "device_close"];