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

With no annotations provided, the description carries the full burden of disclosing behavior. It explicitly says 'No disk access,' which is a critical safety trait: the tool performs no filesystem reads or writes. It stops short of stating the return format or what 'safe' means, but the most important behavioral constraint is clearly disclosed.

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 only two sentences and the main action is front-loaded: 'Check whether a path looks safe.' The second sentence, 'No disk access,' is efficient and adds essential context without fluff. Every word earns its place.

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 simple path-shape checker, the description covers the core safety concern. However, it never defines what 'safe' means, doesn't describe the return value despite no output schema, and the input schema includes many seemingly unrelated parameters (ref, url, city, feed, host, json) that the description doesn't explain or acknowledge, leaving some ambiguity for an agent.

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 already provides descriptions for every parameter, including 'File path to check' for the path field. The tool description adds no meaning beyond indicating that 'path' is the subject, which the schema already states. Therefore the schema does the heavy lifting and the description contributes no extra parameter-level insight.

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: 'Check whether a path looks safe.' The added 'No disk access' helps distinguish it from tools that actually fetch or validate resources, and the word 'path' separates it from URL-oriented siblings. It is clear, though it doesn't explicitly name any sibling it is not.

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 explicit when-to-use guidance, no alternative tool names, and no exclusion conditions. 'No disk access' is a behavioral trait rather than usage guidance, so the agent must infer when this tool is appropriate instead of being told.

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