List categories

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

Annotations already declare this as a read-only, idempotent, non-destructive operation, so the safety profile is covered. The description adds real behavioral context beyond that: counts include out-of-stock products, and 'tv' hides hundreds of SEO subcategories that duplicate the same products, which prevents the agent from misreading inflated category counts.

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?

Three short paragraphs, each front-loaded and carrying a distinct point: return shape, argument behavior, and the SEO-subcategory caveat. The 'tv' example duck-types slightly into prose, but it earns its place by preventing a concrete failure mode.

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 no output schema, the description still conveys the return shape (slug, product count, ordering) and the default scope. Combined with the sibling hand-off, an agent has everything needed to call this correctly on the first try.

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 coverage is 100%, so the baseline is 3, but the description adds value the schema does not: it explains what the empty-argument case returns (top-level sections) and frames `parent` and `query` as two mutually distinct expansion paths rather than just two optional strings.

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?

States a specific verb and resource ('List shop categories') plus the fields returned and ordering ('with slug and product count, biggest first'). This is clearly distinguishable from siblings like bn_brands or bn_search without opening any schema.

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?

Explicitly covers the no-argument default ('returns the top-level sections'), the two argument paths ('Use `parent` to open one, or `query` to search all of them'), and routes the agent onward to bn_browse by telling it to pass the slug as `category`.

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