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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals only that no browser is launched, but does not say whether the tool makes a network request, has side effects, what it returns, or what discarding inputs means for the 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?

The two sentences are tightly written and front-loaded: the purpose comes first, followed by a key constraint. No words are wasted, though the terse style may be too spare for the schema's complexity.

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?

Given nine optional parameters, no annotations, and no output schema, this description is insufficient. It does not explain how to choose among the parameters, what 'can be opened' means, or what kind of result to expect, so an agent cannot reliably invoke the tool.

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 schema already provides per-parameter descriptions for all nine parameters, so the baseline is 3. The tool description adds no parameter-level insight and does not resolve how the unrelated-looking parameters (ref, city, json, path, query) relate to checking a URL.

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 action – check whether a URL can be opened – and adds a useful constraint that no browser is launched. However, it never clarifies what 'can be opened' means (syntax validity vs reachability), and the 9-parameter input schema includes unrelated values such as city, ref, and json, leaving the tool's actual purpose ambiguous.

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 only usage guidance is the implicit exclusion that no browser is launched, which hints not to use it when browser rendering is needed. It does not name alternative tools such as fetch-status, normalize-url, or playwright-url-ok, nor does it define conditions for when this tool should be selected.

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