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

With no annotations present, the description carries the behavioral disclosure burden. It does disclose a key behavior: no disk access, which tells an agent this is a safe, non-mutating validation. However, it does not explain what 'looks safe' means, what the tool returns, or whether it can error on unexpected input.

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 clauses: an action statement and a key constraint. It is front-loaded, contains no filler, and 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?

With no output schema and no annotations, the description leaves out important information for correct invocation: what a 'safe' path means, what the return value looks like, and how to interpret the many unrelated schema properties. An agent given only this description would be uncertain about how to call the tool correctly beyond passing `path`.

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 high, with every parameter having a description, so the baseline is 3. The tool description adds no parameter-level meaning beyond reinforcing the `path` param. The presence of many unrelated params (`ref`, `url`, `city`, `feed`, `host`, `json`) is confusing and the description does nothing to clarify which parameter is actually relevant.

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 a specific verb ('check'), resource ('a path'), and criterion ('looks safe'), and adds 'No disk access' to distinguish it from filesystem-touching tools. It is clear and immediately recognizable, though 'safe' is somewhat vague and could mean traversal safety, syntax validity, or access permissions.

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 offers no guidance on when to use this tool instead of siblings like `normalize-url`, `wiki-title-ok`, or `browser-url-ok`. 'No disk access' implies use for safe, side-effect-free validation, but no explicit when/when-not conditions or alternative routes are provided.

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