chewy_facets

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

No annotations are provided, so the description carries the full burden. It discloses that no products are returned, that the call is smaller than sibling product calls, that filter narrows the listing and counts describe the narrowed set, and that unrecognized group_id returns a 404. It also reveals the seo_hvf_slug for brands. It does not explicitly state read-only or safe behavior, but that is implied by the nature of the call. Missing pagination or limit details, but overall transparent.

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 dense paragraph but every sentence adds value. It front-loads the purpose and then layers in usage, output details, and error behavior. While it is longer than ideal, it is structured logically and avoids fluff. No redundant or filler sentences.

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 absence of an output schema, the description provides a comprehensive picture: it explains the structure of facets (options with counts), the brand slug, filter semantics, required parameters, and error handling. It also tells the agent how to use the output as filter pairs. This is complete for a facets-listing tool.

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 baseline is 3. The description adds meaning beyond the schema: it explains the one-of requirement for group_id/q, the filter usage (repeatable, up to 10) and its effect on counts, and the relationship between facets and filters. It also clarifies that each facets[].value paired with an option value becomes a filter key:value. This adds substantial semantic value.

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's purpose: 'List a Chewy category or search's refinement options.' It identifies the specific resource (Chewy categories and searches) and action (listing facets). It also distinguishes it from siblings by explicitly noting 'No products are returned, so this is a much smaller call than chewy_category/chewy_search' when only the option set is needed. This provides strong differentiation.

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 gives explicit guidance on when to use this tool: 'when only the option set is wanted' and contrasts it with chewy_category/chewy_search. It also specifies the required input ('Exactly one of group_id or q is required') and explains how the filter parameter affects the results. It clearly states the 404 behavior for unrecognized group_id, which helps avoid misuse.

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