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

With no annotations, the description carries the full behavioral burden. It usefully discloses 'No disk access', implying the check is side-effect-free and purely syntactic, but it does not describe what happens on success/failure, whether it returns a boolean, or what 'safe' entails.

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 with no filler: the first names the action and target, the second adds the key no-I/O 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?

For a simple predicate, the description is minimally adequate: it names the purpose and the no-disk-access boundary. Yet with no output schema and no annotations, the agent still lacks the exact return contract and the definition of a 'safe' path, so the description is not fully complete.

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 has 100% parameter description coverage, so the baseline is 3 and the description does not need to repeat parameter details. However, the schema exposes many unrelated optional properties, and the description offers no guidance about which parameter is relevant, creating mild ambiguity despite the path property itself being documented.

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 clear verb ('Check'), a resource ('path'), and a criterion ('looks safe'), which is enough to distinguish it from URL-focused siblings like browser-url-ok. It does not, however, define what 'safe' means or what the tool returns, so it stops short of fully unambiguous.

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 such as the other shape-checking siblings. 'No disk access' hints that it is a lightweight validation step, but the description never states a preferred use case, prerequisites, or exclusions.

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