List Payment Capabilities

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

The description adds behavioral context beyond the annotations: 'Nao executa operacoes financeiras, apenas informa capacidades' (Does not execute financial operations, only informs capabilities). While annotations already indicate readOnlyHint and non-destructive, the description clarifies the tool's role as an informational listing, which is useful for the agent.

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, front-loaded with the main purpose, and uses explicit warnings. No unnecessary words or redundancy, earning the highest score.

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 simple parameterless, read-only discovery tool, the description fully covers what it does, what it doesn't do, and when not to use it. No output schema is present, but the return value is implied to be a list of capabilities. Complete for this context.

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 zero parameters, and the input schema is empty (100% coverage). The description does not need to explain parameters. Baseline for 0 params is 4, as there is nothing to clarify.

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 specific verb and resource: 'Mostra tudo que este MCP consegue fazer' (Shows everything this MCP can do), clearly establishing it as a capabilities listing tool. This distinguishes it from sibling execution tools like create_transaction or create_customer, which perform concrete financial actions.

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?

Explicit guidance is provided: 'NAO use este tool quando o usuario pedir uma acao concreta (criar cliente, PIX, etc.) — nesses casos va direto para a tool de execucao' (Do not use this tool when the user asks for a concrete action—go directly to the execution tool). This clearly states when NOT to use and points to alternatives.

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