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

Goes well beyond annotations by disclosing cost ($0.25 per call, billed in bitcoin over Lightning), the one-call-per-payment constraint, and the credential handshake (invoice + macaroon, then macaroon:preimage). Annotations only declare readOnlyHint and openWorldHint, so this payment and auth detail is genuinely additive. It stops short of covering failure modes, macaroon expiry, or what an unpaid second call returns.

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?

Front-loads the return value, then pricing, then the call sequence, so the most useful information comes first. Three dense sentences with minor redundancy between "$0.25 a call" and "one call per payment" that could be merged.

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?

With one optional parameter, no output schema, and read-only annotations, the description carries the needed load: it names the returned fields, the price, and the full payment flow. Remaining gaps (semantics of 'level', error behavior on invalid macaroon, data freshness) are modest for a tool of this complexity.

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% and the schema already documents the "<macaroon>:<preimage>" format and that it follows the first call's invoice, so the baseline applies. The description adds a little context by explaining where the two components originate, but it supplies no format edge cases or validation rules beyond the schema text.

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?

States a specific resource and payload: "The live BTC Intel Score (0 to 100), its level and its date." The word "live" implicitly separates it from the get_delayed_score sibling, but the description never names or contrasts with that alternative explicitly.

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?

Gives an explicit two-phase invocation sequence: call without "payment" to receive an invoice and macaroon, pay externally, then call again with payment = "<macaroon>:<preimage>". That is clear operational context. It does not say when to prefer this paid live score over the sibling get_delayed_score, so the alternative-selection guidance is missing.

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