prepare_design_doc
Call this when the user runs /design-doc. Gathers local git context and the section template, and returns drafting instructions. You (Claude) then draft the actual document from this template plus your own knowledge of what was just done in this session, and finally call save_design_doc with the ...
This record as markdown: /tools/design-doc-generator-mcp/prepare-design-doc.md
What prepare_design_doc does on Design Doc Generator
AI agents call prepare_design_doc to retrieve information from Design Doc Generator without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
mode | string | — | Document mode: 'default' for a standard design doc, 'root-cause' for a bug investigation, or 'comparison' for an approach comparison. Infer from the nature of t |
projectRoot | string | — | Absolute path to the project root. Defaults to the server's current working directory. |
sessionSummary | string | Yes | Your own summary, in your words, of the technical work done in this session so far: the problem, what was tried, what changed, and any alternatives or open issu |
Parameters from the server's own tool schema.
Why prepare_design_doc is rated Low
The tool reads local git context and retrieves a section template, then returns instructions. It does not write, execute, delete, or move money. The actual document creation is done by a subsequent call to save_design_doc. Gathering git context is a read operation with minimal blast radius.
From the tool's definition Gathers local git context and the section template, and returns drafting instructions
Attacks that exploit this kind of access
The rule that runs prepare_design_doc safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Design Doc Generator, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For prepare_design_doc, this is the rule to start with:
prepare_design_doc is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Design Doc Generator, apply this rule, and every prepare_design_doc call is checked against it from then on.
Questions about prepare_design_doc
Call this when the user runs /design-doc. Gathers local git context and the section template, and returns drafting instructions. You (Claude) then draft the actual document from this template plus your own knowledge of what was just done in this session, and finally call save_design_doc with the result. It is categorised as a Read tool in the Design Doc Generator MCP Server, which means it retrieves data without modifying state.
prepare_design_doc accepts 3 parameters: mode, projectRoot, sessionSummary. Required: sessionSummary. The full parameter table on this page comes from the server's own tool schema.
Register the Design Doc Generator MCP server in PolicyLayer and add a rule for prepare_design_doc: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Design Doc Generator. Nothing to install.
prepare_design_doc is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the prepare_design_doc rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for prepare_design_doc. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
prepare_design_doc is provided by the Design Doc Generator MCP server (design-doc-generator-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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