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

With no annotations provided, the description bears the full burden of behavioral disclosure. It reveals only that this is a lookup operation, but says nothing about what happens for unknown codes, whether the 'code' parameter is expected as a number like 404 or a string like '404', or whether omitting the optional parameter returns the full status-code list.

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?

Single sentence, efficiently sized for a simple lookup tool. Slight redundancy exists in the 'HTTP Status:' prefix restating 'HTTP status codes' later in the same short sentence, but there is no wasted scaffolding.

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 one-parameter tool the bar is low, but there is no output schema, no annotations, and no statement of accepted input format or behavior when 'code' is omitted (it is not required). An agent cannot reliably know, e.g., whether '200' or '200 OK' or no argument is the correct invocation.

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% — the 'code' parameter has a description ('Code to process') in the schema — so the baseline is 3. The tool description adds no meaning beyond the schema but is not required to per the rubric at this coverage level.

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 ('Look up') and resource ('HTTP status codes'), making the basic purpose unambiguous. However, the sibling x402-http-codes likely serves an overlapping or identical function, and nothing in the description differentiates this tool from it, so it falls short of a 5.

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 guidance is provided about when to use this tool versus alternatives. The sibling list contains x402-http-codes and x402-http-analyze, which may be closely related, but the description neither names them nor states any selection condition.

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