repo_map

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description reinforces this with 'Read-only, deterministic, zero side effects.' It adds useful context beyond annotations by specifying the output format ('markdown summary') and the intended session-start usage, which provide extra behavioral clarity.

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

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

The description is front-loaded with the core purpose, then safety, then usage guidance, and ends with output format. Every sentence adds value; the structure is clear and easy to scan. There is minimal redundancy beyond reinforcing the read-only nature.

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

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

For a parameterless tool with no output schema, the description is complete: it states the artifact produced, the timing of use, the exclusions, and the alternatives. An agent has everything needed to select and invoke the tool correctly.

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

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

The tool has zero parameters, so the schema carries no burden and there is nothing to document. The description compensates by clarifying what the tool returns ('markdown summary'), which is the relevant semantic context for a parameterless tool.

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

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

The description opens with a specific verb and resource: 'Retrieve a high-level structural map of the repository' and lists the content (languages, hub files, top entry points). It also distinguishes itself from siblings by explicitly naming repo_search and repo_neighbours as alternatives for other tasks.

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

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

Provides explicit guidance on when to use it ('call this first at session start', 'Use when deciding where to investigate') and when not to use it, naming the correct sibling tools for search and call-graph inspection. This fully routes an agent to the right tool with no ambiguity.

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