l402_payment_verify

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

With no annotations, the description carries the full burden. It transparently explains the three verification layers (preimage, HMAC, caveats) and states the return value ('valid: true/false'). It doesn't mention error handling or side effects, but for a verification operation this is adequate, though not exhaustive.

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 short and well-structured with a numbered list. It front-loads the purpose and avoids extraneous detail. Every sentence earns its place.

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 no output schema and no annotations, the description covers the essential aspects: purpose, verification logic, and return type. It lacks details on failure modes or how the resource parameter aligns with caveats, but for a verification tool this is reasonably complete.

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 coverage is 0% and there are no parameter descriptions, so the description must compensate. It links parameters to their roles: 'preimage proves payment', 'HMAC signature proves authenticity' (macaroon), and 'caveats (expiry, resource) are satisfied'. However, it doesn't explicitly clarify how the 'token' parameter relates to the others, leaving some ambiguity.

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 tool's function: 'Verify an L402 payment token submitted by a client.' It uses a specific verb ('verify') and resource ('L402 payment token'), and is well-distinguished from sibling tools like l402_pay (which creates tokens) and l402_discover.

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 gives clear context: this is for verifying tokens submitted by clients. It doesn't explicitly mention alternatives or when not to use, but the purpose is unambiguous given the verb and the token type. Since it lacks explicit exclusions or alternative mentions, it falls short of a 5.

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