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. It states what the tool does but reveals nothing about its behavior: whether it's read-only, what output format to expect, if it requires network access, or if there are rate limits. For a tool with zero annotation coverage, this is a significant gap in 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 with zero wasted words. It's front-loaded with the core purpose, making it immediately clear what the tool does without unnecessary elaboration.

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 lack of annotations and output schema, the description is incomplete for a tool that likely returns structured data about an invoice. It doesn't hint at what information is decoded (e.g., amount, destination, expiry) or the format of the response, leaving the agent unprepared for the tool's behavior and output.

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%, with the single parameter 'invoice' documented as a 'BOLT11 Lightning invoice'. The description adds no additional semantic context beyond this, such as examples of valid invoices or common errors. 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 ('decode') and target resource ('a Lightning invoice'), making the purpose immediately understandable. However, it doesn't differentiate this tool from sibling tools like 'decode_tx' or 'validate_address', which might also involve decoding or validation operations in the Lightning context.

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. With siblings like 'decode_tx', 'validate_address', and 'pay_invoice' available, there's no indication of whether this tool is for validation, analysis, or preparation for payment, leaving the agent to guess about appropriate contexts.

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