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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=true, so safety is covered. The description adds a crucial behavioral disclosure: that prices are asking prices and no realized-sale data is available because Reverb retired its Price Guide. This goes beyond annotations and is essential context for interpreting results. It does not cover pagination quirks or rate limits, but with annotations carrying the safety profile, this is sufficient.

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 zero fluff. The first sentence front-loads the action and scope, the second delivers the critical pricing caveat. Every clause earns its place, and the description is appropriately sized for the tool's complexity.

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 tool with 18 parameters and no output schema, the description covers the essential behavioral caveat (asking vs. sold prices) and lists the returned fields. It does not enumerate all filter combinations, but the schema covers that. It omits return format details, but the description's field list partially compensates. Given the annotations and schema richness, the description is sufficiently complete for an agent to call correctly.

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 every parameter has a description in the schema. The tool description mentions filterable dimensions (category, price band, year range, condition, make, region) that map to parameters, but adds no new meaning beyond what the schema already provides. It does not compensate for any gaps because there are none, so the 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 action ('Search live Reverb.com listings') with a clear resource scope (musical gear) and enumerates the return fields (asking prices, make, model, year, finish, condition grade, seller). It differentiates from sibling tools by its search nature, and the caveat about asking vs. sold prices adds a distinctive purpose that no other sibling covers.

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 usage for searching listings but does not explicitly contrast with siblings like reverb_categories, reverb_listing, or reverb_shop. There is no 'use this when' or 'not for' guidance, though the schema and tool name make it reasonably clear. It leaves the routing decision to the agent without explicit exclusions.

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