aps_verify_settlement

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

With no annotations, the description carries the behavioral transparency burden. It discloses the return format ({valid: true} or {valid: false, reason, detail}), highlights the strongest invariant (S3 conservation) and its security implication. It could mention error handling for malformed records, but the provided details are meaningful.

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 two sentences with no filler. It front-loads the action and scope, then adds the key invariant and return format. 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?

For a read-only verification tool, the description is quite complete: it lists the verification criteria (S1-S5), describes the return shape, and explains the optional parameter behavior. The lack of an output schema is partially mitigated by the return format. Minor gaps include not explaining terms like 'residual shape' for unfamiliar agents, but this is acceptable for domain-specific tools.

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 baseline is 3. The description adds semantics beyond the schema by explaining that passing inputReceipts triggers S5 cross-checking and recomputes input_receipts_hash, and that gateway_public_key is the Ed25519 key for verification. This added context justifies a 4.

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 uses a specific verb ('Verify') plus a specific resource ('a signed SettlementRecord') and scopes it to S1-S5 checks (signature, Merkle roots, conservation, residual shape, optional input-receipts cross-check). This clearly distinguishes it from sibling verify tools like aps_verify_attribution_primitive.

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 clearly indicates when to use the tool (to verify a signed SettlementRecord) and provides guidance on the optional inputReceipts parameter to enable an additional cross-check. It does not explicitly name alternatives or list exclusion conditions, but the context is sufficient for an agent to select it appropriately.

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