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

With no annotations at all, the description carries the full burden. It discloses a real behavioral trait ('No disk access'), which is important. However, it does not say what a 'safe' check returns, how invalid inputs are handled, or what guarantees 'looks safe' provides, leaving gaps in the payoff for an agent.

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 exactly two sentences, front-loads the core action, and keeps a key qualifier ('No disk access') short. It earns its place without waste, though it could have used a third sentence to clarify return semantics.

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 no output schema and no annotations, the description is too thin: it does not explain expected return ('ok?' boolean, errors), define what a 'safe' path is (absolute vs relative, traversal, etc.), or address the 8 unrelated optional parameters. An agent would need to infer most of the calling contract.

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 coverage is 100%, so each parameter already has descriptive text. The description does not add further parameter context, but it doesn't need to repeat the schema; baseline 3 is applied. Some confusion remains because many optional params (ref, url, city, feed, etc.) appear irrelevant to a path-checking tool, a schema-level issue rather than a description issue.

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?

States a specific verb 'check' and resource 'a path', and clarifies the check is a safety/shape validation with 'looks safe'. It is not a tautology and is understandable for a single-purpose tool, though it does not explicitly differentiate itself from sibling shape-checkers like domain-shape or jira-key-shape.

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 on when to use this tool versus alternatives, and no mention of which of the 9 optional parameters actually matter for the stated purpose. 'No disk access' implies a cost/hint but does not explain when to prefer this over other validators or how to handle the many unrelated parameters.

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