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

With no annotations, the description carries full responsibility for behavior; the 'No disk access' statement is a valuable and explicit side-effect guarantee. But it does not disclose whether the tool returns a boolean, what safety rules are applied, how invalid inputs are handled, or which parameter(s) it checks, leaving significant behavior unspecified.

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 a single, front-loaded sentence with no wasted words: the core purpose comes first, followed by a useful side-effect qualifier. It is appropriately sized for a simple checker, though it sacrifices detail that is penalized in other dimensions.

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?

For a tool with 9 optional parameters, no output schema, no annotations, and many sibling validators, this description is too thin. It omits the return value, whether the 'path' parameter is the intended input, what 'safe' covers, and how to distinguish this from similar shape-check tools, so an agent cannot confidently invoke it correctly.

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 the baseline is 3; each parameter already has a clear description, and 'path' directly says 'File path to check.' The description adds no parameter-level meaning and does not disambiguate the several seemingly unrelated optional parameters (ref, city, feed, json, zone, query) present in the schema.

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' and adds a clarifying side-effect constraint, 'No disk access.' It is clearly distinct from sibling URL/domain/title validators by focusing on file paths, although it never defines what 'safe' means or explicitly contrasts with those siblings.

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 phrase 'No disk access' implies this is a pure syntactic safety check and should not be used to verify real file existence, which is useful context. However, there are no explicit when/when-not rules or named alternatives, so the agent must infer when to choose this over sibling shape-checkers.

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