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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It does convey that the tool checks reachability and follows redirects to a final destination, implying a non-destructive network operation. However, it omits details such as whether it actually fetches content, timeout behavior, or what exact response format is returned, leaving some ambiguity.

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 sentence, front-loaded with the primary action and resource, and contains no extraneous information. Every word contributes to understanding the tool's function.

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?

For a simple single-parameter tool with no output schema, the description provides a complete high-level understanding of what the tool does: it checks reachability and reports the final destination after redirects. While it does not detail return structure, the tool is simple enough that the description is sufficient for selection and invocation.

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 input schema has a single 'url' parameter with no description, and schema coverage is 0%. The description explicitly refers to 'a single URL', which clarifies that the parameter expects a single URL string. This adds minimal meaning beyond the schema, but it does not specify URL format requirements (e.g., must include protocol), so it only partially compensates for the lack of schema detail.

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 uses a specific verb ('probe') with a clear resource ('a single URL') and states the tool's purpose: checking reachability and finding the final destination. It distinguishes itself from the sibling tools, which focus on citations, making the tool's function unambiguous.

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 clearly indicates the tool is for probing a single URL, which sets a clear usage context. However, it does not explicitly state when to use this tool over alternatives or provide exclusions, though the sibling tools are unrelated to URL probing, so the guidance is adequate without needing explicit alternatives.

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