discover_skills

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

With no annotations, the description carries the full burden. It explicitly discloses the directories scanned and the exact fields returned, which is useful behavioral context. It doesn't explicitly state it's read-only, but the 'scan' verb implies a non-destructive operation, and the level of detail is sufficient for a scan tool.

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 three sentences with no wasted words. The first sentence front-loads the core purpose, the second specifies the return type, and the third lists the search paths. Every sentence adds essential information, making it efficient and easy to parse.

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 scan tool with two optional parameters and no output schema, the description is fairly complete. It covers the purpose, search locations, and return format. The only missing element is explicit guidance on when to use it over siblings, but that is addressed under usage guidelines, and the description provides enough for an agent to invoke it correctly.

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 covers 100% of parameters with descriptions for dir and filter_by_keys. The description adds no additional parameter context, so the baseline of 3 applies. The schema already explains the parameters adequately.

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 ('Scan') and resource ('current project and installed npm packages for available skills'), and details the output structure (manifests with id, name, etc.). It clearly distinguishes itself from a generic listing tool by specifying the scan targets and the structured return format, making its purpose unambiguous.

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 sibling tools like list_skills or list_byok_keys. It states what it does but doesn't mention alternatives or exclusion criteria, leaving the agent to infer when discovery is preferred over listing.

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