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

No annotations are provided, so the description carries the behavioral transparency burden. It does disclose a meaningful privacy trait: 'Page content is not stored.' However, it does not mention network access, rate limits, or that the many non-URL input parameters are irrelevant, leaving some behavioral context unspecified.

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 two short sentences with no filler. The main action and outputs are front-loaded, and the second sentence is a relevant caveat. Every word earns its place.

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 is adequate for a small metadata/status tool, and the schema compensates for parameter ambiguity. However, with nine optional parameters and no output schema, it would be clearer if the description explicitly stated that only the URL parameter is used and the others are ignored. This is a modest but real gap.

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 description coverage is 100%, and each parameter already has a description, including the relevant 'url' field. The description adds the connection between URL input and the host/scheme/status output, but it does not meaningfully clarify parameter selection beyond what the schema already provides. Baseline 3 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 clearly states what the tool does: 'Return host, scheme, and HTTP status for a URL.' This is a specific action with concrete outputs and is not a tautology. It does not explicitly distinguish from sibling tools like fetch-status or normalize-url, but the stated purpose is understandable on its own.

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 explicit 'use this when' statement or named alternative tool. The caveat 'Page content is not stored' weakly implies this is for metadata/status rather than content retrieval, but the agent must infer routing from that. This is implied usage guidance, not clear exclusions or alternatives.

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