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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the description only needs to add extra context. It does add that results are 'ranked' and include 'canonical URLs,' but it does not disclose any other behavioral details such as ordering, scoping, or limitations.

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 with no filler. The primary purpose is front-loaded, and the usage guidance is clear and short, making it easy for an agent to process quickly.

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 description gives a basic sense of output and usage, but the tool has three parameters, no output schema, and a closely related sibling tool, search_corpus. An agent still cannot infer when to prefer this tool over search_corpus or what the 'song' parameter does.

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 0%, so the description must compensate for the three parameters. It explains that the query is a 'focused historical or lyrical question,' but it does not explain the 'song' parameter or the meaning of 'limit,' leaving important parameter semantics undocumented.

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 uses a specific verb, 'Return ranked corpus excerpts and canonical URLs,' and names the target resource clearly. It is easy to understand what the tool does, but it does not explicitly differentiate from sibling tools like search_corpus, so it stops short of a 5.

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 provides a clear usage context: 'Use this to ground research before interpretation.' This tells the agent when the tool is appropriate, but it does not give exclusions or name alternatives, which would be needed for a 5.

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