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

With no annotations provided, the description carries the full burden. It adds one behavioral note ('Page content is not stored'), but omits critical traits: which parameters are discarded, whether network calls are made, and the behavior for non-URL parameters. It also fails to clarify that many parameters are validation-only as implied by the schema, leaving the tool's actual behavior ambiguous.

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 short (two sentences) and front-loads the purpose, which is structurally efficient. However, the brevity comes at the cost of necessary detail—it is under-specified rather than concisely complete. It earns a middle score for being tidy but inadequate.

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?

This is a 9-parameter tool with no annotations and no output schema. The description is grossly insufficient: it does not explain the purpose of the other 8 parameters, how they relate to the stated output, or how to choose the correct input. An agent cannot confidently invoke this tool based on the description alone.

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 coverage is 100%, so the baseline is 3. The description does not add any parameter-level meaning beyond the schema; it only mentions 'a URL' without specifying the 'url' parameter or how other parameters interact. It neither contradicts nor enhances the schema, so a baseline score is appropriate.

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 verb ('Return') and resource (host, scheme, HTTP status for a URL), but it is ambiguous which of the 9 parameters corresponds to the URL. It does not differentiate from siblings like 'fetch-status' or 'normalize-url', and the description implies the tool only handles URLs while the schema includes many non-URL parameters (city, zone, query, etc.), making the purpose unclear.

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?

There is no guidance on when to use this tool versus alternatives. No mention of when-not-to-use, prerequisites, or which sibling to prefer. The description provides zero context for tool selection.

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