x402 crypto market structure

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

No annotations are provided, so the description carries the full burden. It describes the tool as informational ('pricing, quick start guide, and migration details'), which suggests a read-only, non-destructive operation. However, it lacks details on authentication requirements, rate limits, response format, or error handling, which are important for behavioral 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, efficient sentence that front-loads the key information ('API pricing, quick start guide, and migration details') without unnecessary words. Every part of the sentence contributes to understanding the tool's purpose, making it appropriately concise and well-structured.

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?

Given the tool's complexity (simple informational with 0 parameters), no annotations, and no output schema, the description is minimally adequate. It covers the purpose but lacks details on output format, error cases, or behavioral constraints. For a tool with no structured fields to rely on, it should provide more context to be fully complete.

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?

The tool has 0 parameters with 100% schema description coverage, so the schema fully documents the absence of inputs. The description doesn't need to add parameter semantics, and it doesn't incorrectly imply any parameters. A baseline of 4 is appropriate for a zero-parameter tool with complete schema coverage.

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 clearly states the tool provides 'API pricing, quick start guide, and migration details' for the 'x402 API' and 'pay-per-call REST endpoint', which is a specific verb (provides) and resource (API documentation). However, it doesn't explicitly differentiate from sibling tools like 'marketAnalyze' or 'marketSnapshot', which appear to be market data tools rather than API documentation tools.

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 implies usage for API information needs but provides no explicit guidance on when to use this tool versus alternatives. There's no mention of prerequisites, context for use, or comparison with sibling tools, leaving the agent to infer usage based on the purpose alone.

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