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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it states the answer is for the server's held API version, unknown paths are reported as not found with nearest existing paths, and nothing is guessed. This is meaningful disclosure of failure behavior and versioning semantics.

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 compact and front-loaded: it opens with the core purpose, then details the contract contents, then covers versioning and failure behavior. Every sentence earns its place, and there is no redundant restatement of the title or schema.

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 lookup tool with two well-documented parameters and no output schema, the description is nearly complete. It covers what the tool returns, versioning behavior, and failure behavior. The only minor gap is that it does not explicitly describe the output format structure, but since there is no output schema and the description lists the contents (signature, parameters, return type, docs, examples), this is adequately covered.

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 the schema already documents both parameters (path and version). The description adds context about the path format (dotted path, example) and the version semantics (omit for server-held version), but it does not add substantial meaning beyond the schema. Baseline 3 is appropriate.

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 states a specific verb ('describe') and resource ('one API member by dotted path'), and enumerates exactly what the contract includes: signature, parameters with type/default/range, return type, documentation, examples, and execution environment. It also distinguishes itself from siblings by focusing on a single member's exact contract rather than listing or searching.

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 implies when to use this tool: when you need the exact contract of one member by dotted path. It also clarifies behavior for unknown paths (reports not found with nearest existing paths, nothing guessed). However, it does not explicitly name sibling alternatives or state when to prefer them, so it falls short of a 5.

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