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

Since no annotations are provided, the description carries the full burden for behavioral disclosure. It states 'Get user detail' but does not describe authentication requirements, error responses, or whether sensitive fields are filtered. There is no warning about rate limits or data freshness.

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 very short and front-loaded, but it is redundant: 'Get user by user name' and 'Get user detail based on username' say essentially the same thing. One sentence would suffice, so the second sentence does not earn its place.

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?

The tool has no output schema and no annotations, so the description must be self-sufficient. It covers the basic look-up purpose but omits return structure, error possibilities, auth requirements, and explanation of the optional header parameter. For a two-parameter tool, this is insufficient.

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 description coverage is 0%. The description adds meaning to the 'username' parameter (identifies the user) but completely ignores the optional 'x-hapi-auth-state' header parameter. No parameter format, default behavior, or interplay between parameters is explained.

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 specifies a clear verb ('Get') and resource ('user') with the key parameter ('user name'). It distinguishes from sibling tools like getPetById and getOrderById by focusing on the user resource. However, it could further clarify whether it returns full user objects or selected fields.

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?

No usage guidance is provided. The description does not mention when to prefer this tool over alternatives like createUser, updateUser, or deleteUser, nor does it state any prerequisites or limitations. This leaves the agent without decision support.

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