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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is established. The description adds the purpose of discovering category paths but does not disclose additional behaviors such as pagination specifics or result ordering. With annotations covering the core behavioral traits, a 3 is appropriate.

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 long and front-loads the primary action, then immediately adds usage context. Every sentence earns its place without redundancy.

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 read-only listing tool with robust schema documentation, the description is nearly complete. It covers what the tool does and why it is useful. The lack of an output schema is acceptable because the return value is straightforwardly implied as a list of categories, and pagination is handled in the schema.

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 input schema already provides 100% parameter descriptions, including retailer_id format, pagination cursor semantics, and limit bounds. The description adds no additional parameter meaning beyond the schema, 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 states a specific verb ('List') and resource ('product categories available for a specific retailer'), which clearly distinguishes it from sibling tools like list_retailers and search_retailer_products. An agent can immediately understand what the tool returns and for whom.

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 sentence 'Use this to discover valid category paths before filtering products by category' provides clear contextual guidance on when to call this tool. It does not explicitly name alternatives or exclusion conditions, but the intended workflow is evident and sufficient for most agents.

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