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

With no annotations present, the description carries the behavioral disclosure burden. It does add one meaningful trait: 'No disk access,' which tells the agent the tool won't touch the filesystem. However, it does not disclose the return format, the meaning of 'ok', whether network access is also avoided, or how the extra schema fields (url, city, feed, etc.) are handled.

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. It front-loads the core purpose and immediately adds the critical no-I/O behavioral constraint. 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 tool appears simple but the schema includes many apparently unrelated parameters (url, city, feed, host, json, ref), and the description does not explain their role or the relationship to path checking. With no output schema and no return-type information, the agent is left guessing what a successful check returns and what 'looks safe' actually validates.

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 input schema has descriptions for every parameter, including 'path' and 'access', so schema coverage is high. The description itself adds no parameter-level meaning, but the schema already documents each field and notes that several fields are discarded after the check. This meets the baseline for well-described schemas.

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 specific verb and resource: 'Check whether a path looks safe.' This is clear and distinct from sibling URL/web tools, and the addition of 'No disk access' clarifies it is a pure shape/safety validation. However, it does not define what 'safe' means (e.g., syntactic validity, path traversal prevention) or what output the agent should expect.

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 explicit guidance is given about when to use this tool versus alternatives like browser-url-ok, playwright-url-ok, or normalize-url. 'No disk access' only implies this tool is for non-I/O checks, but it never states exclusions or recommends another tool for actual filesystem verification or URL validation.

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