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

Annotations are not provided, so the description carries the burden of disclosing behavior. It does mention that 'Page content is not stored,' which is a form of behavioral transparency about data retention. However, the description is incomplete: it does not disclose that many parameters are 'discarded' (e.g., 'ref' is discarded), which is a behavioral trait. It does not state whether the tool has side effects, caching, or rate limits. Given the lack of annotations, the description should be more explicit about these behaviors.

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 short and front-loaded with the purpose, but it lacks structure. It does not enumerate the parameters or explain the multiple modes of operation. The sentence 'Page content is not stored.' is appended without context. While it is concise, it is under-specified for a tool with 9 parameters.

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 complex tool with 9 parameters and no output schema. The description is far from complete: it does not explain how the parameters interact, which are mutually exclusive, or what the exact output format is. It does not provide examples or enough information to use the tool correctly. The description does not cover the breadth of functionality implied by the parameter list.

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%, so each parameter has a description. However, the description adds confusion by listing parameters that seem unrelated to the primary purpose (e.g., 'city', 'query', 'json'). The description does not explain how these parameters relate to the main task of returning host, scheme, and HTTP status. It fails to clarify that many parameters are extras or validation checks, and does not help an agent decide which parameters to use together.

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 that it returns host, scheme, and HTTP status for a URL, which is a specific verb and resource. However, the tool takes many parameters that do not all relate to a URL (e.g., city, feed, json, path, zone, query), making it unclear what the actual purpose is. It might be a generic dispatcher, but the description does not clarify that, and it does not distinguish it from siblings like 'normalize-url' or 'fetch-status'.

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. It does not mention any conditions for using it over siblings like 'browser-url-ok' or 'fetch-status'. It only says what it returns, not when it should be used. The lack of required parameters and the broad set of inputs suggest it might be a general utility, but the description does not explain that.

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