Lightning Wallet MCP

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions the critical requirement 'REQUIRES AGENT KEY' which is valuable, but lacks other important details like whether this is a destructive/mutative operation, potential rate limits, error conditions, or what happens on success/failure. For a payment tool with zero annotation coverage, this is insufficient.

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 appropriately concise with two clear sentences. The first sentence states the core functionality, and the second provides a critical prerequisite. There's no wasted verbiage, though it could be slightly more structured with bullet points for the requirement.

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 payment tool with no annotations and no output schema, the description is incomplete. While it mentions the agent key requirement, it doesn't cover important behavioral aspects like whether funds are immediately transferred, what confirmation looks like, error handling, or security implications. The agent should understand more about this financial operation's consequences.

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 three parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. According to scoring rules, when schema coverage is high (>80%), the baseline is 3 even with no param info in the description.

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 ('Send a payment') and resource ('directly to a node without an invoice'), distinguishing it from invoice-based payment tools like 'pay_invoice'. However, it doesn't explicitly differentiate from other spontaneous payment methods like 'nostr_zap' or 'pay_lightning_address', which prevents a perfect score.

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 by specifying 'without an invoice', suggesting this is for direct payments when invoices aren't available. It doesn't provide explicit when-not-to-use guidance or name alternatives like 'pay_invoice' for comparison, leaving some ambiguity about optimal use cases.

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