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

Annotations already declare readOnlyHint=true, and the description reinforces with 'Read-only, no authentication required.' It adds valuable context beyond annotations: the data is 'static', callable once and cacheable for the session, and includes policy URLs. This goes beyond what the annotations alone convey.

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 information-dense but well-organized: it opens with the tool's purpose, then presents a logical list of returned data categories, and closes with usage guidance. Every clause contributes actionable information; despite length, there is no redundancy or filler.

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?

With an empty input schema and an output schema available, the description covers everything an agent needs: what kind of data is returned, how it should be used, its read-only and auth-free nature, and a caching strategy. Nothing essential is missing.

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 tool has zero parameters and the input schema is empty, so there is no parameter semantics to clarify. The rubric baseline for 0 parameters is 4; the description adds no parameter-specific meaning, but none is needed.

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 identifies a specific verb ('Returns'), a clear resource ('static reference data'), and a precise purpose ('build valid searches and read responses without guessing'). It enumerates the exact contents, making the tool's role unmistakable among operation-focused siblings like products.create and offers.make.

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 states when to call the tool ('once and cache for the session') and why ('an agent needs to build valid searches and read responses'). It explicitly ties outputs to downstream usage, e.g., 'use these for search's category filter', giving clear guidance absent any alternative metadata tool.

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