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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions 'No browser is launched,' which is a negative constraint, but it does not explain whether a network request occurs, what validation is performed, or any side effects. This leaves the agent uninformed about the tool's actual behavior.

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 one short sentence, which is concise and front-loaded, but it is under-specified. While it avoids verbosity, it lacks any structural breakdown or additional context, making it insufficiently informative for the tool'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?

This tool has 9 parameters, no annotations, and no output schema, so the description must provide comprehensive context. It does none of that—it gives a one-line vague statement that fails to explain the tool's behavior, parameter relationships, or return values. This is completely inadequate for an agent to use 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?

Schema coverage is 100%, so the baseline is 3, but the tool description adds no semantic context for the parameters. It fails to explain why a URL-open check would need parameters like 'city', 'zone', 'json', or 'path', and the schema descriptions alone do not clarify their role in this tool's purpose. The description does not compensate for the apparent mismatch.

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 a resource (URL), which is better than a tautology. However, it is vague about what 'opened' means (e.g., does it perform a network request or just validate format?) and does not differentiate it from siblings like browser-url-ok or fetch-status. The many unrelated parameters further cloud the actual purpose.

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 gives no guidance on when to use this tool versus alternatives such as browser-url-ok or fetch-status. There is no mention of preferred scenarios, exclusions, or prerequisites, leaving the agent without context for selection.

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