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

The description discloses the key non-behavior 'No disk access' and uses the hedged phrase 'looks safe,' signaling that this is a heuristic/syntactic check rather than a guarantee. However, it doesn't state what 'safe' means, what the return value looks like, or that inputs are 'discarded after the check'—that detail is left to the schema property descriptions.

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?

Two short sentences, and each one carries distinct information: the core purpose and the critical no-disk-access constraint. Nothing is redundant or padded.

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 schema contains seven heterogeneous optional parameters, yet the description doesn't explain which one to pass or whether they are mutually exclusive. There is also no output schema or mention of the return shape, so an agent has insufficient guidance to call the tool correctly based on the description alone.

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?

Each input property already has a descriptive schema entry, so schema coverage is effectively 100% and the baseline applies. The description itself adds no parameter-level guidance, though the schema's 'File path to check' makes the intended path argument reasonably clear.

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 action ('Check') and a clear resource ('whether a path looks safe'), and the 'No disk access' qualifier distinguishes it from tools that inspect real files. However, it doesn't reference sibling validators or explain why the schema exposes six other unrelated fields such as url, city, feed, and json, which keeps it from being a 5.

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 choose this tool over alternatives like domain-shape, wiki-title-ok, or browser-url-ok. 'No disk access' implies a syntactic use case, but there is no explicit when-to-use, when-not-to-use, or alternative routing.

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