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

The description says 'No browser is launched' and implies URL checking, but the parameters suggest the tool validates a wide range of data shapes (e.g., JSON, timezone, search text) and discards inputs afterward. This is a major contradiction between the stated behavior and the actual operation. With no annotations, the description carries full burden, and it fails to disclose what the tool truly does, any side effects, or return values.

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 only two short sentences and is concise with no filler. However, it is under-specified for a tool with nine parameters, so while it is concise, it sacrifices necessary detail. The structure is acceptable but not front-loaded with the most critical information.

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?

Given nine optional parameters, no output schema, no annotations, and a description that only mentions URL checking, the tool is severely incomplete. An agent would not know what the tool returns, how to interpret the parameters, when to invoke it, or what errors may occur. The description fails to provide the context needed for reliable use.

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 covers all 100% of parameters with individual descriptions, so the baseline is 3, but the tool description adds no value to parameter understanding. The mismatch between the declared URL-checking purpose and the diverse parameters (e.g., city, path, zone) makes it unclear how to use them correctly.

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 'Check whether a URL can be opened', which is a clear verb-resource pair, but the input schema accepts nine diverse parameters including city, json, path, zone, and query that have no relation to URLs. This makes the stated purpose misleading and fails to convey the tool's actual function as a multi-type shape validator.

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 provided on when to use this tool versus siblings like browser-url-ok or fetch-status. There are no conditions, exclusions, or mention of alternatives, leaving the agent without any decision support.

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