Find where a symbol is defined

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

With no annotations, the description carries the full burden of explaining behavior. It discloses matching semantics (bare/qualified names, substring fallback) but does not mention other important traits such as case sensitivity, behavior on multiple matches, or whether the repo parameter is required for scoping. The provided behavior is useful but incomplete.

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 two sentences long and front-loaded with the primary purpose. Every sentence adds value: the first states the core function, the second explains input flexibility and fallback behavior. There is no filler or redundancy.

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?

The tool has 3 parameters and no output schema or annotations. The description adequately covers the name parameter and overall purpose, but it lacks explanation of the repo parameter and expected return value or error behavior. It is not a complex tool, but the gaps in parameter and output information make it incomplete.

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 only 33% (only 'name' is described). The description adds meaningful semantics for 'name' (bare/qualified, substring matching) but says nothing about 'kind' or 'repo'. Since coverage is low, the description should compensate fully, but it only partially does so, leaving two of three parameters unclear.

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 clearly states the tool's purpose: 'Locate the definition of a function, class or method by name.' It specifies a concrete verb and resource, and the scope (by name) distinguishes it from siblings like who_calls and what_it_calls, which focus on call relationships rather than definitions.

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 useful context on accepted name formats ('bare name' or 'qualified one') and fallback behavior ('substring matching'), which implies when to use it. However, it does not explicitly state when to prefer this tool over siblings or provide exclusions, so guidance is more implied than explicit.

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