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

The only behavioral disclosure is 'No browser is launched,' which is a limitation but not a full picture. It does not state whether the tool makes network requests, what side effects might occur (e.g., redirects, cookie handling), or any permissions/rate limits. Since annotations are absent, this sparse disclosure is insufficient.

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 a single, concise sentence, which is easy to read. However, it lacks structure (e.g., examples, parameter groupings, return-value hints) and is too terse to be fully helpful, especially given the complex 9-parameter schema.

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 is minimal and does not cover the tool's full context: no return value/output schema, no error conditions, no mention of how the extra parameters should be treated, and no relation to sibling tools. For a tool with 9 parameters and no annotations, this is severely incomplete.

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?

While every parameter has a description, several are explicitly marked as discarded (e.g., 'ref' says 'discarded after the shape check', 'query' says 'discarded after the length check'), implying they are irrelevant placeholders. This confuses rather than clarifies. The 'url' description ('HTTPS URL to normalize or cite') contradicts the tool's stated purpose of checking openability. No guidance on which parameters are required or how they interact.

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 action ('Check whether a URL can be opened') and resource (URL), but the meaning of 'can be opened' is ambiguous—does it involve an HTTP request, DNS resolution, or something else? It does not distinguish itself from sibling tools like 'fetch-status' or 'playwright-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?

There is no guidance on when to use this tool versus alternatives. It does not mention any conditions, exclusions, or relationships to sibling tools, leaving the agent to guess which tool fits a given scenario.

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