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 behavioral disclosure. It only says 'catalog', implying a read-only reference, but does not explicitly state whether it returns a list, a single code, or how the 9 input parameters are used. The mismatch between the description and the wide-ranging parameters (ref, url, city, etc.) is unexplained, leaving the tool's behavior opaque.

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 sentence, which is concise and front-loaded. However, for a tool with 9 parameters and no output schema, this brevity borders on under-specification. The sentence states the purpose but lacks any structure or supplementary sections (e.g., examples, notes). It earns a 3 because it is efficient but not well-rounded.

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 9 parameters, no required fields, no output schema, and no annotations. The description must compensate by explaining what the tool does with these inputs, what it returns, and any constraints. A one-line statement about a 'catalog' is completely inadequate for an agent to call this tool correctly. This is a severe gap in completeness.

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 description coverage is 100%, so each parameter has a description. The tool description adds no meaning beyond the schema—it does not connect the parameters to HTTP status codes or any function. Since the schema already documents each parameter's individual purpose (e.g., 'discarded after the shape check'), the baseline of 3 is appropriate; the description contributes no additional semantic value.

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 'Short catalog of common HTTP status codes' clearly states the resource (HTTP status codes) and the action (provides a catalog). It is specific enough to convey the tool's core function. However, it does not distinguish this tool from siblings like fetch-status or browser-url-ok, which could also involve HTTP status codes, so it loses a point for lacking sibling differentiation.

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 indication of when to use this tool versus alternatives. It does not mention prerequisites, typical use cases, or when to prefer another tool. There is no guidance on exclusions or alternatives, so an agent must infer usage entirely from the tool name and schema.

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