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

The description discloses one important behavior (no browser launch), but it does not clarify what constitutes 'can be opened' (e.g., HTTP status, DNS resolution), what happens on failure, timeouts, or if any side effects (e.g., network requests, cookies) occur. With no annotations, the description carries the full burden and falls short.

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 extremely brief and to the point, using only two sentences. It wastes no words and is well structured for quick reading.

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?

The description lacks critical context: it does not explain the purpose of the nine parameters, the expected output, error handling, or how it differs from similar tools. Given the abstract schema and many optional parameters, the description is far from complete.

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 parameters have descriptions, but they are unrelated to URL checking (e.g., 'city' for weather, 'ref' for git) and appear to be placeholders. The tool description does not clarify their meaning or relevance to the URL check, making the parameters confusing and effectively unexplained.

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 primary action ('Check whether a URL can be opened') and even clarifies a key behavioral aspect ('No browser is launched'). However, it does not distinguish itself from sibling tools like browser-url-ok or fetch-status, which might serve similar purposes.

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. There is no mention of specific scenarios, limitations, or conditions that would make this tool preferable to others.

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