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

With no annotations, the description carries full responsibility for behavioral disclosure. It specifies the return object shape ({name, markdown, meta}), explains what markdown and meta contain, and describes the error-key behavior with available names when the skill does not exist. The 'Fetch' verb also conveys a read-only operation.

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?

Three sentences with the core operation front-loaded, followed by return shape and edge-case handling. Every clause adds necessary information, and there is no redundant or promotional language.

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 one-parameter read tool, the description covers purpose, identifier source, output structure, and not-found behavior. The presence of an output schema further reduces the need for additional return-value detail, so nothing essential is missing.

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 only parameter, name, has no description in the schema (0% coverage), but the description compensates by defining it as a slug from list_skills. This gives the agent concrete provenance for valid values, far beyond the bare schema title 'Name'.

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 opens with a specific verb and resource: 'Fetch one compiled skill by name'. It also names the source of valid identifiers ('slug from list_skills'), which clearly distinguishes this tool from list_skills and other sibling tools.

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 phrase 'slug from list_skills' gives clear operational context: an agent should first call list_skills to get names before using get_skill. It does not explicitly name alternatives or state when not to use it, so it stops just short of full routing guidance.

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