List product categories

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds value by disclosing the return content (subcategories and product counts) and the optional brand scoping, but does not describe deeper behavior like pagination or ordering. This matches the baseline for annotation-covered simple tools.

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 single, front-loaded sentence that efficiently conveys the core purpose, the included details (subcategories, counts), and the optional brand scoping. No unnecessary words or repetition.

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 simple list tool with one optional parameter and good annotations, the description is complete. It explains what the tool returns (categories with subcategories and product counts) and the optional brand filter, which sufficiently covers the agent's needs. No output schema exists, but the description covers return value basics adequately.

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% for the single optional parameter (brand_id). The description's 'optionally scoped to a brand' paraphrases the schema without adding new syntax or format details. Baseline 3 is appropriate because the schema handles the parameter documentation.

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 uses a specific verb ('List') with a specific resource ('product categories') and adds differentiating details: it includes subcategories and product counts, and can be scoped to a brand. This clearly distinguishes it from siblings like list_brands (lists brands) or create_category (creates categories).

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 provides clear context for when to use the tool: it lists product categories, optionally filtered by brand. It implies the primary use case (listing categories with subcategory/count info) without explicitly naming alternatives or exclusions, which is acceptable for a simple list tool.

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