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

With no annotations, the description carries a heavy burden and does disclose a key behavior: no disk access, meaning it is a pure shape check. It also honestly says 'looks safe' rather than guaranteeing safety. But it does not describe the return value or failure behavior, so it remains 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?

Two short, front-loaded sentences with no filler. The purpose comes first and the key side-effect disclaimer is stated immediately after, making this exceptionally efficient.

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 tool has no annotations, no output schema, and a surprising 9-parameter schema, yet the description explains only path and says nothing about return values. The mismatch between the narrow description and the broad schema leaves an agent unable to fully understand when or how to use the other parameters.

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 parameters are already individually documented. The description adds meaning only for path ('looks safe', no disk access) and does not clarify the role of the other eight parameters, leaving agents unsure whether they are alternative inputs or irrelevant.

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 uses a specific verb and resource: checking whether a path looks safe, and clarifies it does no disk access. This makes its core function clear, but it ignores the many other properties in the schema (url, city, json, etc.), so the stated purpose is narrower than the input schema suggests.

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 description implies use when you need a side-effect-free path safety check, and 'No disk access' signals it is a safe pre-check. However, it gives no explicit guidance on when to choose this tool over sibling validators like browser-url-ok or normalize-url, and offers no exclusions.

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