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

Annotations already declare readOnlyHint=true, and the description reinforces this by stating no API key needed. It discloses what the tool returns (full SKILL.md or version string) and the content of the guide, adding value beyond the annotations without contradiction.

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 well-structured sentences: first describes the resource, second states prerequisites, third gives usage with the parameter. No fluff; every sentence serves a purpose.

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 read-only tool with one optional parameter and no output schema, the description covers all needed context: what it returns, why you'd use it, how the parameter works, and that no authentication is needed.

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?

Schema coverage is 100% for the single boolean parameter, providing a baseline of 3. The description adds extra context: 'to tell whether a cached copy is current', which helps the agent understand the parameter's utility.

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 it retrieves the relay's SKILL.md guide covering events vs records, schema grammars, and poll loop. This distinguishes it from all sibling tools which are other operations (agent, apps, etc.).

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 explicitly says 'Needs no API key' and suggests using it when working out how tools fit together or to refresh a cached copy. It also explains the version_only parameter purpose, giving clear guidance on when to use which variant.

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