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

With no annotations provided, the description carries the burden of behavioral disclosure. It adds meaningful context by clarifying that coverage reflects what each supplier's SOURCE stated, not product quality, and that a one-supplier category is reported honestly rather than presented as a comparison.

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 first sentence states the core output, and the second provides an essential caveat about data interpretation. It is front-loaded and each sentence 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?

Given the single enum-constrained parameter and no output schema, the description communicates the key output dimensions: counts, share, and per-facet data coverage. It does not fully define these terms, but the tool is simple enough that an agent can select and invoke it 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?

The schema covers the single parameter fully with an enum and a description pointing to list_categories. The tool description does not add new parameter-level meaning, so the baseline score of 3 applies.

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 identifies the tool's purpose: reporting which suppliers cover a category, with counts, share, and per-facet data coverage. It is specific about the resource and scope, though it does not explicitly differentiate it from siblings like list_brands or get_brand.

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 intended use is implied: when you want supplier coverage for a category. However, there is no explicit guidance on when to choose this tool over sibling tools such as list_brands, nor any exclusions or alternative conditions.

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