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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the tool's safety profile is known. The description adds that it returns slugs and UUIDs, which is useful but not behavioral in nature. It does not describe any side effects or additional constraints, so the description adds moderate value beyond the annotations.

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 a single, well-structured sentence that front-loads the purpose and provides concrete examples of content. There is no redundant information, and every part earns its place.

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 reference tool with no output schema, the description is sufficient. It explains what the tool returns (category tree with slugs and UUIDs), how it is used (filters in reverb_search), and the optional filter (root_slug). An agent can confidently decide when to call this tool and what to expect.

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?

The input schema already documents the only parameter (root_slug) with a description and example, achieving 100% coverage. The description does not add new semantics for the parameter beyond listing root categories, which is already implicit in the schema. Since the schema handles the parameter explanation, a baseline of 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 clearly states the tool returns the Reverb.com category tree, lists the root product types, and explains it provides slugs and UUIDs used for filters on reverb_search. This distinguishes it from sibling tools like reverb_search, which focuses on searching listings, and reverb_listing, which likely deals with individual listings.

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 the tool is used to obtain category identifiers for constructing reverb_search filters, which is a clear use case. It does not explicitly mention when not to use it or alternative tools, but the context is strong enough for an agent to infer its purpose.

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