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

No annotations are provided, so the description carries the full burden of disclosure. It reveals only that no browser is launched, but does not state whether a network request is made, what 'opened' means, or any side effects. This is thin coverage for an action verb like 'check.'

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?

Two short sentences with no filler. The key behavioral scoping fact, 'No browser is launched,' is front-loaded and earns its place by differentiating from sibling tools.

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 tool has a complex, heterogeneous schema and no output schema. The description only states the primary action, ignoring parameter semantics, expected return values, or the role of extraneous fields. An agent would lack essential information to call it correctly.

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 never mentions parameters, while the schema contains seven unrelated-looking fields (ref, city, feed, path, etc.). The url field is described as 'HTTPS URL to normalize or cite' in the schema, which conflicts with the tool's 'can be opened' purpose. The description adds no connective tissue to resolve this ambiguity.

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 clear verb-resource pair: 'Check whether a URL can be opened.' The second sentence, 'No browser is launched,' distinguishes it from sibling tools like playwright-url-ok. However, it does not define what 'opened' means (e.g., HTTP status vs. syntax), which keeps it from being fully unambiguous.

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 explicit when-to-use guidance or alternatives are given. The 'No browser is launched' note implies a lightweight, quick check compared to browser-based siblings, but this is left to inference rather than stated.

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