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

No annotations are provided, so the description carries full burden. It discloses the signing/payment model ('5 free trial calls per signed wallet'), which is useful, but says nothing about how the four overlapping params are resolved, whether multiple may be supplied, or what happens when they conflict.

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?

Two short clauses, front-loaded with the purpose. The pricing note is compact, though it occupies space that could have addressed param precedence.

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?

No output schema and no annotations, so the description must explain behavior fully. It covers purpose and billing but omits the critical ambiguity resolution among four near-duplicate params and any return-value shape.

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 0% across four params (ext, name, filename, extension) that clearly overlap in meaning. The description gives no guidance on precedence or which to use, leaving the agent unable to resolve the ambiguity.

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?

States a specific verb (Detect) and resource (MIME type from filename extension), which is clear and actionable. It lacks explicit differentiation from siblings like x402-mime, x402-mime-detect, or x402-file-ext-info, which appear to overlap.

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 contextual detail is a pricing note about free trial calls. There is no guidance on when to use this versus the very similar x402-mime, x402-mime-detect, or x402-file-ext-info siblings, and no mention of prerequisites.

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