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

The description discloses that page content is not stored, which is a behavioral note. However, it does not mention network access, side effects, or any other behavior beyond this single fact, leaving partial transparency.

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 concise, consisting of two short sentences. It is well-structured, with no unnecessary verbosity, and efficiently conveys the core functionality.

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 having 9 parameters, the description only mentions a URL and does not explain how other parameters like 'ref', 'city', 'feed', 'json', 'path', 'zone', or 'query' fit into the tool's operation. There is no output schema, and the description's output details are minimal. The tool's behavior with these parameters is completely unclear, making the description insufficient for the tool's complexity.

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 cover 100% of parameters, so the baseline is 3. The description itself adds no extra meaning to parameters beyond what the schema already provides, so it does not improve the score.

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 specific and identifiable purpose. However, it does not differentiate from sibling tools like 'fetch-status' or 'normalize-url' which may have overlapping functionality.

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. There is no mention of scenarios where this tool is preferred, nor any exclusion of other tools, leaving the agent without usage direction.

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