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

With no annotations provided, the description carries the transparency burden. It discloses return fields and a non-storage guarantee, but does not mention error behavior, ignored parameters, or any side effects beyond not storing content.

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, front-loaded with the action and output, with no redundant words.

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 the simple promise, the context includes 9 optional parameters and no output schema, and the description does not clarify which parameters are relevant or how to invoke the tool correctly. It is not complete for an agent facing this ambiguous schema.

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 all 9 parameters, but the top-level description adds no parameter meaning and does not map 'URL' to the url property. Since schema coverage is high, this is acceptable but not improved by the description.

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 and explicitly says page content is not stored. It could be more specific about which sibling tools it complements, but the core purpose is understandable.

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 given about when to choose this tool over siblings like fetch-status or normalize-url. The only additional statement is a non-storage guarantee, which is behavioral rather than usage direction.

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