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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It only states that it is a 'short catalog,' which implies read-only behavior but doesn't clarify whether it makes network requests, returns a static list, or processes inputs. The parameter set (url, host, json, zone) suggests behavior completely different from what the description implies, adding confusion rather than transparency.

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, but it is under-specified and provides no structured overview. It doesn't front-load critical information about the tool's operation, and its vagueness outweighs any benefit of brevity.

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?

For a tool with four parameters and no output schema, this description is grossly insufficient. It doesn't explain what the tool returns, how the parameters are used, or any example usage. The inconsistency with sibling tools (e.g., normalize-url, validate-json, timezone) further compounds the incompleteness, as an agent cannot infer the intended functionality.

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?

Although schema description coverage is 100%, each parameter's description (e.g., 'HTTPS URL to normalize or cite', 'JSON text to validate; discarded after the check') is generic and unrelated to HTTP status codes. The tool description does not connect these parameters to its stated purpose, so it adds no meaning beyond the schema. The mismatch between parameters and purpose warrants a score below the baseline of 3.

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 claims the tool is a 'catalog of common HTTP status codes,' but the input schema requires url, host, json, and zone parameters that have no evident relation to HTTP status codes. This creates a fundamental mismatch, making the purpose unclear and potentially misleading. No verb or resource is specified, and it fails to distinguish from siblings like normalize-url or validate-json.

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. The description offers no scenarios, prerequisites, or exclusions, leaving an agent without any basis for selecting it over similar tools.

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