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

The description explicitly says 'No disk access', which is a useful safety trait. However, it does not disclose any other behavior, such as whether it returns a boolean or an error, or whether it might validate other parameters like the schema's unrelated fields.

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 with two short sentences and no redundant information. It directly states the purpose and a key safety trait, making it easy to parse quickly.

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 description omits essential details such as the definition of 'safe', the return type, and how to interpret the other schema parameters. Given the tool's simplicity, the lack of these details makes it incomplete for correct invocation, especially with the mismatched schema.

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 description adds no meaning about parameters; the schema descriptions are the only source. While the 'path' parameter is explained, the other eight parameters (e.g., 'ref', 'url', 'city') are described in a generic way that seems unrelated to the tool's stated purpose, creating potential confusion.

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 clearly states the verb 'Check' and the resource 'whether a path looks safe', which is distinct from sibling URL-checking tools like 'browser-url-ok'. However, it does not specify what constitutes 'safe' or how it differs from a simple existence check.

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 gives no indication of when to use this tool versus alternatives, nor does it mention any prerequisites or context. It only states the action without guiding the agent on appropriate scenarios.

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