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

Annotations already declare readOnly, idempotent, and non-destructive, so the description's addition of 'as seen by the server' and the proxy-injected headers adds valuable behavioral context about networking specifics. No 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?

A single sentence with high information density; the most critical descriptive info ('as seen by the server') appears early, and every clause adds value.

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 is simple (no params, read-only, no output schema), the description covers all essential aspects: what it returns and its purpose. The absence of a detailed output format is acceptable.

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?

No parameters exist, so the description needs to clarify the scope and return. It states it returns 'all HTTP request headers' with specific proxy headers, which gives the agent a clear expectation of what the output will contain.

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?

Clearly states it returns all HTTP request headers as seen by the server, with a verb and resource. It differentiates from siblings by mentioning proxy-injected headers, but doesn't explicitly name sibling tools or their scope.

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 'Useful for debugging proxies and client identity' provides clear context for when to use it. Although it doesn't explicitly say when not to use it, the context is sufficient given the sibling tools are distinct.

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