Bitcoin MCP Server

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. 'Pay a Lightning invoice' implies a financial transaction with real-world consequences, but the description doesn't disclose critical traits like whether it's irreversible, requires specific permissions, has rate limits, or what happens on failure. This leaves significant gaps for a tool handling payments.

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 with zero waste. It's front-loaded with the core action and resource, making it easy to parse quickly. Every word earns its place, adhering perfectly to conciseness standards.

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 complexity of a payment tool with no annotations and no output schema, the description is insufficient. It lacks details on behavioral traits (e.g., idempotency, error handling), return values, or integration context. For a financial operation, this leaves the agent with critical unknowns about execution and outcomes.

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 input schema has 100% description coverage, with the 'invoice' parameter documented as a 'BOLT11 Lightning invoice'. The description adds no additional meaning beyond this, as it doesn't explain invoice format, validation, or usage context. With high schema coverage, the baseline score of 3 is appropriate, as the schema does the heavy lifting.

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 action ('Pay') and the resource ('a Lightning invoice'), making the purpose immediately understandable. It doesn't explicitly differentiate from sibling tools like 'decode_invoice' or 'get_transaction', but the verb 'Pay' implies a transactional operation rather than informational retrieval.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing funds or authentication), when not to use it, or how it relates to sibling tools like 'decode_invoice' (which might be a precursor). Usage is implied by the action but lacks explicit context.

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