list_categories

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds the permission requirement 'INVENTORY_R' and the 'all' scope, which provides some context beyond annotations. However, it does not disclose details like pagination, ordering, or handling of empty results, which could be relevant.

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 short sentences, each adding value: what the tool does and what permission is needed. There is no fluff or repetition. It is front-loaded with the core purpose and highly efficient.

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 tool's simplicity (no parameters), the presence of a readOnlyHint and openWorldHint, and an output schema, the description is complete. The permission requirement is a crucial operational detail. No additional behavioral explanation is necessary for this straightforward list operation.

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 tool has zero parameters, so the description need not explain parameter semantics. The schema covers everything with 100% coverage (vacuously). Baseline for 0 params is 4, and the description adds no unnecessary parameter information, which is appropriate.

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 function: 'Return all inventory categories.' The verb 'return' and resource 'inventory categories' are specific and unambiguous. The permission requirement 'Requires INVENTORY_R' further clarifies the scope. This distinguishes it from sibling list tools like list_tags or list_attributes.

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 implies usage: when you need inventory categories, use this tool. However, it provides no explicit guidance on when to use this versus alternatives, nor does it mention any exclusion scenarios. The permission requirement is a prerequisite, not usage guidance.

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