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

The description includes one behavioral note ('Page content is not stored') implying a read-only operation, but it does not disclose potential network side effects, rate limits, or failure modes. The significant mismatch between the description and the actual schema parameters (which include unrelated fields like city, json, query) further undermines transparency about what the tool actually does.

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 a single, focused sentence that efficiently communicates the primary output. However, it omits any mention of the input parameters or the relationship between the tool name and its function, which slightly detracts from its completeness while remaining concise.

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 complexity of 9 optional parameters and no output schema, the description is insufficient. It does not explain which parameters are relevant for a URL citation task, how they relate to the stated output, or what the response format is. The agent would be uncertain about how to properly invoke this tool.

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 provides descriptions for all 9 parameters (100% coverage), so the baseline is set to 3. The tool description itself adds no additional meaning to any parameter, and the parameter descriptions appear generic and unrelated to URL handling, but the description is not responsible for repeating schema content. This meets the minimum adequacy threshold.

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 clearly states the tool returns host, scheme, and HTTP status for a URL, which is a concrete purpose. However, it does not differentiate this from sibling tools like fetch-status or normalize-url that likely perform similar URL inspection tasks, leaving ambiguity about when to select this one.

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 no guidance on when to use this tool versus alternatives. It lacks any mention of prerequisites, typical use cases, or conditions under which it should be preferred, leaving the agent to guess.

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