module_summary

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds behavioral context beyond that: the tool summarizes a file's defined symbols, imports, and dependents as computed via the call graph. This clarifies what the agent should expect without repeating annotation data.

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?

Two sentences, no filler. The definition is front-loaded and the usage guidance is actionable. Every word contributes to either clarifying the tool's output or telling the agent when to invoke it.

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 read-only summary tool with fully documented parameters and safety annotations, the description provides sufficient context. It states what the output covers (symbols, imports, dependents) even without an output schema, though it could more explicitly mention how the optional 'source' parameter affects results.

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 schema covers all parameters with descriptions at 100% coverage, so the baseline is 3. The tool description does not add parameter-level details, but it does contextualize the primary 'file' parameter by describing the file-as-a-unit scope. No additional compensation is needed.

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 defines a clear scope: one file as a unit, covering the symbols it defines, imports, and dependent files via the call graph. It also supplies a direct action ('Read it before editing a file you don't know'), which makes the purpose unmistakable and distinguishes it from symbol-level tools like describe_symbol and impact.

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?

The description gives an explicit use case: read this before editing an unfamiliar file. It does not explicitly enumerate when not to use it or name alternative tools, but the context is clear enough for an agent to decide when module_summary is the right starting point.

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