list_skills

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the API key is optional and 'shows usage if provided,' which hints at authentication and potential usage tracking. However, it lacks details on rate limits, pagination, error handling, or what 'shows usage' entails. For a tool with no annotation coverage, this leaves significant behavioral gaps.

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 concise and front-loaded, with the core purpose stated first. The additional note about the API key is brief and relevant. However, the structure could be improved by integrating the parameter note more seamlessly or adding a line break for clarity, but overall, it avoids unnecessary verbosity.

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 (1 optional parameter) and the presence of an output schema (which likely covers return values), the description is minimally adequate. It states the purpose and hints at authentication behavior. However, with no annotations and incomplete parameter semantics, it doesn't fully address potential agent needs, such as error cases or performance considerations, leaving room for improvement.

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 description adds minimal semantics beyond the input schema. It notes that the API key is 'optional' and 'shows usage if provided,' which provides some context not in the schema (which only lists it as a string with a default). However, with 0% schema description coverage and 1 parameter, the description doesn't fully compensate—it doesn't explain what 'usage' means or how the key affects output. The baseline is 3 due to the single parameter, but the added value is limited.

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 all available skill files with descriptions.' It specifies the verb ('List') and resource ('skill files'), and mentions the inclusion of descriptions. However, it doesn't explicitly differentiate this from sibling tools like 'get_skill' (which presumably retrieves a specific skill), leaving some ambiguity about when to use each.

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 no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'get_skill' (for retrieving a specific skill) or 'register' (which might involve skills), nor does it specify prerequisites or contexts for usage. The only contextual hint is the optional API key parameter, but this doesn't constitute usage guidance.

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