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

With no annotations provided, the description carries the full disclosure burden, and it does so thoroughly. It explains that the tool throws on low score, dead endpoint, or UNKNOWN status, describes free-tier gating, and notes the unlock paths. This is well beyond typical descriptions.

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?

Three sentences, each earning its place: the core gate and failure behavior, the free-tier caveat and unlock path, and the mandatory call ordering. It is front-loaded and contains no filler.

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?

The description covers failure modes, UNKNOWN handling, the gated service URL, and how to unlock it. The only notable gap is that it does not describe the success return value, but since the tool throws on failure, the no-throw outcome is reasonably inferable as a pass.

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 schema only gives default values for minScore and requireAlive. The description adds real meaning by explaining minScore is the reputation threshold and requireAlive is the liveness gate, and by clarifying that UNKNOWN or absent values fail require* gates. It adds value beyond the schema, though address semantics are left mostly to the pattern.

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 identifies a concrete operation: vet an agent against a reputation minimum and a liveness gate before payment. It states the resource and the timing, but it does not explicitly differentiate itself from similar pre-payment or gate-like siblings such as mainstreet_preflight or lawbor_gate.

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 explicitly says 'Always call BEFORE x402 payment' and repeats the before-payment positioning in the first sentence. It gives clear when-to-use context, though it does not name alternatives or state when not to use the tool.

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