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

Annotations already declare readOnlyHint and openWorldHint=false, so the safety profile is covered. The description adds genuine context beyond that: the visibility constraint that only repositories whose owners opened them to agents are queried, and the shape of the returned data (file, line, signature). Pagination and result-limit behavior remain unstated.

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 with no padding, and the core purpose is front-loaded before the access caveat. The final clause about repository owners is slightly convoluted in phrasing but earns its place as scope information.

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 only three parameters, full schema coverage, annotations covering safety, and no output schema, the description supplies the missing pieces an agent needs: what is returned and which repositories are searched. Ambiguity handling (multiple matches, default repo scope) is the only notable omission.

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 coverage is 100%, so the schema already documents all three parameters including the 'Class.Method' whose-form and the path/repo filters. The description's 'Ask by name, or Class.Method to say whose' largely restates the schema. Baseline 3 applies when the schema carries the parameter load.

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 names a specific resource and verb: locating where a class, method or function is *declared*, and returns file/line/signature. That is meaningfully narrower than search_code or read_code. It stops short of naming a sibling to differentiate against, leaving the agent to infer the boundary.

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?

'Ask by name, or Class.Method to say whose' explains how to call it, not when. There is no explicit contrast with search_code, code_calls, list_code or read_code, so an agent must infer that this is the declaration-lookup tool rather than a text search or call-graph tool.

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