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

No annotations are present, so the description bears full responsibility for behavioral disclosure. It does mention 'Page content is not stored,' which is a useful privacy note, but it remains silent on network side effects, permission requirements, or why nine distinct input parameters exist when the description only mentions URL. The presence of many seemingly irrelevant parameters (city, feed, json, etc.) that are 'discarded' is unexplained, creating confusion about actual behavior.

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 just two sentences, front-loading the primary action and adding a privacy caveat. It is concise and without fluff, though it may be too brief given the tool's complexity. It earns a high score for economy of wording.

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?

Despite the schema covering parameters, the description leaves many contextual gaps: it does not specify the return format, explain the purpose of the nine diverse parameters, or clarify whether all parameters are alternatives or if only 'url' matters. With no output schema and no annotations, an agent cannot confidently infer how to invoke this tool correctly beyond passing a URL.

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 100%, so each parameter already has a meaningful description in the schema. The tool description adds no additional parameter-level context beyond what the schema provides. Per the calibration baseline, a score of 3 is appropriate when the schema fully covers parameters and the description does not compound on it.

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 clear action: 'Return host, scheme, and HTTP status for a URL.' This is a specific verb-resource pair that at least distinguishes it from tools like 'calc-eval' or 'think-steps'. However, it does not reference sibling tools or explain how it differs from 'fetch-status' or 'normalize-url', so it falls short of full differentiation.

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 does not mention any prerequisites, conditions, or exclusions. An agent would have no explicit signal to choose this over 'fetch-status' or 'browser-url-ok'.

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