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

Beyond the readOnlyHint annotation, the description discloses the exact return content (Markdown with summary, metadata, install command, and skill file) and the URL structure for identifiers. This adds meaningful behavioral context without repeating the annotation.

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 two sentences with no filler. The first sentence front-loads the primary purpose and output, and the second sentence provides the parameter derivation rule. Every element is purposeful.

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 read-only tool with two simple parameters, no output schema, and readOnlyHint annotations, this description covers the essential invocation details: what to pass, how to derive it, and what will be returned. No critical information for an agent to call it correctly 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?

Even though the input schema already describes both parameters with 100% coverage, the description adds a relational mapping (owner and name as last two URL segments), which clarifies how the two parameters connect and how to derive them. This goes beyond the schema's individual descriptions.

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 action ('Get one skill') and the resource ('skill') with a precise output format ('as Markdown: summary, metadata, install command and the full skill file'). It also explains the owner/name mapping to pageUrl, which clearly differentiates this from siblings like search_skills or install_skill by specifying a single, identifiable skill.

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 on how to construct the owner and name from the skill's pageUrl, which is a practical usage guideline. However, it does not explicitly mention when not to use this tool or point to alternatives like search_skills when the skill slug is unknown, so it lacks explicit exclusion conditions.

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