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

The annotations already declare it as read-only, idempotent, non-destructive, and closed-world. The description adds a meaningful behavioral detail not covered by annotations: using an unknown category returns the category list rather than an error or empty result.

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 definition is two short sentences, front-loaded with the primary action and followed by the category-discovery tip. There is no redundant or wasted text.

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 one-parameter listing tool with full schema coverage and clear annotations, the description is nearly complete. It could mention the return shape, such as whether it returns tool names or full definitions, but that is a minor gap.

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%, and the single parameter is already documented with type, example, and slug semantics. The description does not add syntax or constraints beyond what the schema provides, 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 and resource: "List every tool in a category." It is clear enough to distinguish from get_tool and search_tools, but it does not explicitly name or contrast with those siblings.

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?

It gives one useful usage rule: call with an unknown category to retrieve the category list. However, it does not explain when to choose this tool over search_tools or get_tool, nor does it state exclusions or prerequisites.

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