Cursor Delegate

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delegate

Destructive

Send coding tasks to Cursor's CLI agent over ACP, auto-approving permissions and returning structured results for review. Resume a session by ID to answer the agent's follow-up questions.

Instructions

Delegate a coding task to cursor-agent over ACP. Never shell out to cursor-agent — use this tool only. Auto-approves every permission the agent requests, in any mode and anywhere on disk. Clarifying questions arrive as prose in result — resume with resumeSessionId to answer. Keep model (composer-2.5), fast and effort at their defaults unless the user explicitly asks. See the delegate skill.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`fast`	No	Fast tier; higher cost — only when the user asks.
`mode`	No	agent implements; plan and ask are instructions to the agent, not limits.	agent
`spec`	Yes	Task brief: goal, scope, fixed decisions quoted exactly, acceptance criteria. Sent as written. Point at files to read rather than pasting code, or attach them with contextFiles.
`model`	No	Bare ACP family id, version included: composer-2.5, grok-4.5, claude-opus-5, gpt-5.6-sol. doctor deep:true lists every id.	composer-2.5
`effort`	No	Exact Cursor thinking-effort value for the selected model. Values differ per model and some expose no effort option; invalid values fail before the prompt and name the accepted set. Pass only when the user asks for Cursor effort — the host's own reasoning setting is unrelated.
`context`	No	Context window size; gpt-5.x accepts 272k and 1m. Do not pass speculatively.
`workspace`	Yes	The agent's working directory, not a limit. Smallest directory holding the task's files; with no such directory the project root is the floor. Must already exist; never create one for the call.
`contextFiles`	No	Paths to attach instead of pasting contents into spec. Text becomes references the agent may open; images (png/jpg/gif/webp, <5MB) are sent inline. Relative paths resolve against workspace but are not limited to it. Skips are reported in protocolWarnings, never fatal.
`resumeSessionId`	No	Continue an existing ACP session.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv2.5.0Oct 7, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```

Changed12 schema fields changedv2.0.0Aug 27, 2026

changedInput schema / properties / context / description

Previous value: -"Context window size. Not offered by every model; gpt-5.x accepts 272k and 1m."New value: +"Context window size; gpt-5.x accepts 272k and 1m. Do not pass speculatively."

changedInput schema / properties / contextFiles / description

Previous value: -"Paths to attach instead of pasting file contents into spec. Text files are passed as references the agent may open; images (png, jpg, gif, webp, under 5MB) are sent inline. Relative paths resolve against workspace, and paths outside it are allowed — attach only files the agent should read. Anything skipped is reported in protocolWarnings, never fatal."New value: +"Paths to attach instead of pasting contents into spec. Text becomes references the agent may open; images (png/jpg/gif/webp, <5MB) are sent inline. Relative paths resolve against workspace but are not limited to it. Skips are reported in protocolWarnings, never fatal."

addedInput schema / properties / effort

Added value: +{
+  "description": "Exact Cursor thinking-effort value for the selected model. Values differ per model and some expose no effort option; invalid values fail before the prompt and name the accepted set. Pass only when the user asks for Cursor effort — the host's own reasoning setting is unrelated.",
+  "minLength": 1,
+  "type": "string"
+}

changedInput schema / properties / fast / description

Previous value: -"Fast speed tier — higher cost; enable only when the user asks"New value: +"Fast tier; higher cost — only when the user asks."

changedInput schema / properties / mode / description

Previous value: -"Requested agent mode. plan and ask are passed to the agent as instructions, not enforced by the bridge — the agent may write in any of them, so review the git diff after every run. ask held on every model tested while plan compliance varies by model, so prefer ask when you need the stricter read-only instruction."New value: +"agent implements; plan and ask are instructions to the agent, not limits."

addedInput schema / properties / model / description

Added value: +"Bare ACP family id, version included: composer-2.5, grok-4.5, claude-opus-5, gpt-5.6-sol. doctor deep:true lists every id."

removedInput schema / properties / reasoning

Removed value: -{
-  "description": "Reasoning effort. Not offered by every model; gpt-5.x accepts none, low, medium, high, extra-high.",
-  "minLength": 1,
-  "type": "string"
-}

changedInput schema / properties / resumeSessionId / description

Previous value: -"Resume an existing ACP session instead of a new one"New value: +"Continue an existing ACP session."

changedInput schema / properties / spec / description

Previous value: -"Inline task brief (default): goal, scope, decisions already made (constraints and fixed choices — quote the user's exact values verbatim), acceptance criteria. Point at files to read or mimic rather than pasting code. Optional file path if the user wants a persisted spec."New value: +"Task brief: goal, scope, fixed decisions quoted exactly, acceptance criteria. Sent as written. Point at files to read rather than pasting code, or attach them with contextFiles."

changedInput schema / properties / workspace / description

Previous value: -"Working directory for the agent (defaults to cwd). Must be an existing directory; the call fails rather than creating it."New value: +"The agent's working directory, not a limit. Smallest directory holding the task's files; with no such directory the project root is the floor. Must already exist; never create one for the call."

addedInput schema / properties / workspace / minLength
```
Added value: +1
```

changedInput schema / required

Previous value: -[
-  "spec"
-]New value: +[
+  "spec",
+  "workspace"
+]

First observedv1.18.0Aug 7, 2026

TDQS

A4.8/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the destructive/openWorld annotations by disclosing that it auto-approves every permission request in any mode and anywhere on disk, and that clarifying questions surface as prose in the result with a documented resume path. These are the exact behavioral traits an agent needs before firing a destructive, non-idempotent call.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Five dense sentences with no filler, and the most critical constraint (never shell out) is placed second. Slightly packed, but every sentence carries an operating rule the agent could otherwise get wrong.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With nine parameters but full schema coverage, no output schema, and destructive/openWorld annotations, the description supplies the missing pieces: permission auto-approval, result-shape expectations (clarifications as prose), session resumption, and safe defaults for the optional knobs.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description adds policy the schema does not express: leave model/fast/effort at defaults unless the user asks, and do not pass context speculatively. That is genuine decision guidance rather than a restatement of field types.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource — 'Delegate a coding task to cursor-agent over ACP' — and immediately rules out the wrong mechanism ('Never shell out to cursor-agent — use this tool only'). An agent can tell this apart from cancel and doctor at a glance.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit when-to-use routing ('use this tool only'), explicit constraint on optional params ('keep model, fast and effort at their defaults unless the user explicitly asks'), and an explicit follow-up path ('resume with resumeSessionId'). Also points at the delegate skill for depth.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

delegate

Instructions

Input Schema

Schema Changelog

TDQS

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