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

With no annotations, the description bears full responsibility. It mentions 'Body discarded' but omits other behaviors such as redirects, timeouts, error handling, or authentication requirements.

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 to the point, with two clear sentences. It avoids unnecessary verbosity.

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 nine parameters and absence of an output schema, the description is far too sparse. It does not explain which parameters are relevant, what the exact input URL should be, or what the response format will be, leaving agents with insufficient information.

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 schema descriptions are misleading (e.g., 'url' says 'normalize or cite' instead of fetching), and the tool description never clarifies that only the 'url' parameter is actually used. The other parameters are described as discarded, but their purposes are unrelated to the tool's stated function.

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 the core function ('HTTP status and content type for a public URL') but does not distinguish it from sibling tools like fetch-status or browser-url-ok, and the schema includes many irrelevant parameters that confuse the primary purpose.

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 guidance is provided on when to use this tool versus alternatives. The description only states what it does, not when it should be chosen over similar tools.

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