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

The description adds a meaningful behavioral trait by explicitly stating 'No disk access', which tells the agent this is a non-destructive, purely syntactic check. With no annotations present, this is helpful, but it does not disclose the return value, error behavior, or the meaning of 'safe' beyond the absence of disk access.

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 two short sentences with no wasted words, and the main purpose is front-loaded in the first sentence. It is appropriately sized for a simple check-like tool and conveys the essential distinction without padding.

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 annotations and no output schema, the description carries the burden of explaining behavior, and it partially succeeds by noting the absence of disk access. Still, it omits what 'safe' means, what the tool returns, and how to handle the unrelated schema parameters, leaving an agent to guess at key invocation details.

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 input schema provides individual descriptions for all seven parameters, including 'File path to check' for path, so schema coverage is high and the description does not need to repeat parameter details. However, the description does not clarify that only the 'path' parameter is relevant and that the other parameters are ignored, which could confuse an agent.

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 ('Check') and resource ('a path'), and adds the key qualifier 'No disk access', which distinguishes it from filesystem-touching operations and sibling URL-checking tools. However, 'looks safe' is somewhat vague without defining what safety criteria are applied.

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?

There is no guidance on when to use this tool versus alternatives like browser-url-ok or wiki-title-ok. The description implies a pure syntactic/path-safety check because it says 'No disk access', but it does not state exclusions or direct the agent to a more appropriate sibling for other cases.

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