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

The description explicitly states 'No disk access,' which is a valuable behavioral guarantee. With no annotations provided, the description carries the full burden, but it only covers this one aspect. It does not disclose whether the tool is read-only, what it returns (e.g., boolean, status), or how it handles invalid inputs. For a validator with nine parameters, more behavioral detail is expected, so this is adequate but incomplete.

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 extremely concise at two sentences, which is efficient. However, it is under-specified for the tool's actual breadth (9 parameters, multiple validation types). Conciseness alone does not make it effective; it omits essential context about the other parameters and the tool's general purpose. It is appropriately short but not sufficiently informative.

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?

Given the tool's complexity (9 optional parameters, no output schema, no annotations), the description is incomplete. It does not explain what 'safe' means, how the tool handles the other parameter types, or what the return value indicates. The lack of an output schema and annotations means the description must carry more weight, but it leaves agents without enough information to use the tool correctly beyond the path case.

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 each parameter already has a description. The tool description adds no additional meaning beyond repeating 'path' and 'no disk access,' which is already in the schema. Since coverage is complete, a baseline of 3 is appropriate; the description does not need to compensate, but it also does not add value beyond 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 the tool checks whether a path looks safe and explicitly notes no disk access, which is clear for the path use case. However, the input schema includes eight other unrelated parameters (ref, url, city, feed, host, json, zone, query), and the description does not mention that the tool can validate these or that it is a multi-purpose validator. This creates ambiguity about the tool's true scope, so purpose clarity is only partial.

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 usage guidance is provided. The description does not say when to use this tool versus the many sibling shape-checkers (e.g., browser-url-ok, figma-url-shape, wiki-title-ok). It also does not explain that different parameters are appropriate for different validation needs or mention any exclusions. Agents must infer applicability from the parameter names alone.

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