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 fails to mention that executing payments may be irreversible, incur costs, or require authentication. It also does not explain what 'fund', 'execute', or 'check' actions concretely do. The description only lists supported protocols, leaving significant risk factors undisclosed.

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 two sentences long, front-loads the core purpose, and provides relevant protocol details without fluff. Every sentence contributes meaning, and it is appropriately compact for a tool with a clear function.

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 five parameters including a nested object, no output schema, and no annotations. The description does not explain return values, differences between action modes, or important operational caveats such as idempotency or failure behavior. For a payment tool, this is a significant gap given the lack of structured output information.

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 the schema already documents all five parameters. The description adds no additional meaning beyond the schema. It does mention 'payment execution' which loosely correlates with the 'execute' action, but this is not a semantic addition to the parameters themselves.

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's purpose: 'Detect payment protocol for any MCP server and route to the correct payment execution.' It names specific supported protocols (x402, MPP, prepaid API keys), which distinguishes it from sibling tools like catalog, inspect, and search. The verb+resource structure is specific and unambiguous.

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 context: it is for payment-related operations on MCP servers. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or when not to use it. The purpose makes it inferable, but there is no direct guidance on selecting this tool over siblings.

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