list_categories

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

No annotations are provided, so the description carries the full burden. It states the tool lists categories and returns a dict with a list of names, which covers basic behavior. However, it lacks details on permissions, rate limits, error handling, or whether this is a read-only operation (implied but not stated). For a tool with zero annotation coverage, this is a significant gap in behavioral disclosure.

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 appropriately sized and front-loaded: the first sentence states the purpose clearly, and the second sentence specifies the return value. There's no wasted text, but it could be slightly more structured (e.g., bullet points) for optimal clarity, so it's not a perfect 5.

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 low complexity (0 parameters, simple list operation), an output schema exists (implied by context signals), and no annotations, the description is fairly complete. It explains what the tool does and the return format. However, it could benefit from more behavioral context (e.g., read-only nature, any dependencies), so it's not a full 5.

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 0 parameters, and schema description coverage is 100% (since there are no parameters to describe). The description doesn't need to add parameter semantics, so it meets the baseline of 4 for tools with no parameters, as per the rules.

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 purpose: 'List available news categories for get_category_feed.' This specifies the verb ('List') and resource ('available news categories'), and mentions the sibling tool get_category_feed. However, it doesn't explicitly differentiate from other sibling tools like get_geo_feed or get_topic_feed, which might also involve categories, so it's not a perfect 5.

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 by referencing get_category_feed, suggesting this tool should be used to retrieve categories for that specific sibling. However, it doesn't provide explicit guidance on when to use this tool versus alternatives (e.g., if other tools also list categories or if this is a prerequisite), and there are no exclusions or clear context beyond the implied link.

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