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

Annotations already cover readOnly, idempotent, non-destructive, and non-open-world. The description adds genuinely non-annotated behavioral context: it never raises protocol errors, returns a structured {"error": ...} on bad input, and is safe to retry. The return-shape sketch overlaps somewhat with the existing output schema, slightly capping the score.

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?

Front-loaded with purpose and the FREE tag, then usage, then behavior. Mostly earns its space, though the verbose return-shape example is somewhat redundant given an output schema exists.

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?

With annotations covering safety, an output schema covering returns, and the description covering error semantics and usage routing, an agent has everything needed to call it correctly. No meaningful gaps remain.

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?

Schema description coverage is 100%, so both parameters are fully documented in the schema. The description's typical-input example adds minor illustration but no semantics beyond what the schema already provides, so it holds at the baseline.

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?

States a specific verb (Report) and resource (structural complexity of a source file, function by function), and explicitly distinguishes itself from security_deep_dive. An agent can identify the tool's scope without opening the schema.

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 when-to-use ("structure rather than correctness") and when-not-to-use ("Not for vulnerabilities (security_deep_dive)"), naming the alternative tool. Routing is unambiguous.

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