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

The description adds valuable behavioral context beyond annotations. Annotations indicate read-only, non-destructive, and idempotent operations, but the description clarifies that it 'Returns the complete SKILL.md content with step-by-step guidance, examples, and file references to follow,' detailing the output format and purpose. This enhances understanding without contradicting annotations, which already cover safety aspects like read-only and non-destructive hints.

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 well-structured and appropriately sized, with key information front-loaded: the first sentence explains the core action and return value. The additional section '# Skills' provides necessary usage context without redundancy. Every sentence serves a purpose, making it efficient, though it could be slightly more concise by integrating the usage guidelines more seamlessly.

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 complexity (simple read operation with one parameter), rich annotations (readOnlyHint, idempotentHint, etc.), and no output schema, the description is reasonably complete. It explains what the tool does, when to use it, and what it returns, covering essential aspects. However, it could benefit from more detail on error handling or output structure to fully compensate for the lack of output schema.

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 has 100% description coverage, with the 'name' parameter documented as 'Skill name from <available_skills>'. The description doesn't add further parameter details beyond what the schema provides, such as examples or constraints. Since schema coverage is high, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't need to given the comprehensive schema.

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: 'Load a skill's full instructions' and 'Returns the complete SKILL.md content'. It specifies the verb ('Load') and resource ('skill's full instructions'), making the action clear. However, it doesn't explicitly differentiate from the sibling tool 'skill-resource', which could help distinguish their specific roles.

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 clear context for when to use the tool: 'When a user's task matches a skill description below: 1) activate it, 2) follow its instructions completely.' This gives explicit guidance on the trigger condition and expected workflow. However, it doesn't mention when not to use it or alternatives, such as how it differs from 'skill-resource'.

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