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

Annotations already cover read-only, non-destructive, idempotent behavior. The description adds one meaningful behavioral fact, no browser launched, but does not clarify whether any network request is made or what 'opened' means. No contradiction with annotations.

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?

One short, front-loaded sentence containing exactly the core action and the critical no-browser qualifier. Every word contributes value.

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?

Despite schema descriptions and annotations, an agent still cannot tell what the return value will be, which parameter is primary, or how 'can be opened' is determined. With seven parameters and no output schema, the description should provide more operational context.

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?

All parameters are already described in the input schema, so the baseline is 3. The description adds no parameter-level guidance and does not explain why unrelated parameters like city, feed, json, or path exist for a URL check.

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?

States a specific action (check) and resource (URL), with a useful qualifier ('No browser is launched'). However, 'can be opened' is ambiguous between syntactic validation and actual reachability, and it does not explicitly differentiate from sibling tools like browser-url-ok.

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?

No guidance is given for when to use this tool versus alternatives such as browser-url-ok, web-fetch, or normalize-url. There are no conditions, exclusions, or preferred scenarios described.

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