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

With no annotations, the description carries the full burden and does so richly: it explains that results are stored and registry checks are not rerun, states the auth model (original paying wallet for x402, or bearer token with verification.read scope), discloses not-found behavior for missing/other-tenant IDs, flags a retrieval service fee requiring spending approval, and warns against automatic payment retries.

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 action and the required identifier type, then layers constraints and cautions. Every sentence is informative, though the cautionary tail (fee, retry, authorization inference) makes the paragraph dense enough that trimming some redundancy with the schema would help.

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?

No output schema and no annotations, so the description must cover behavior and returns; it does both by enumerating the stored result states (RELEASE/REVIEW/BLOCK/INSUFFICIENT_EVIDENCE) and the ownership/auth requirements. Nothing needed to call it correctly is missing.

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 verification_id UUID and the IDs not to supply. The description largely restates this (tenant/wallet ownership, wrong-ID types), adding reinforcement rather than new syntax or format detail, so baseline 3 applies.

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 verb+resource (read an existing identity/VAT verification) and anchors it to its producer (verify_supplier_payment / POST /v1/verifications). It explicitly carves itself out from siblings, noting it neither reruns registry checks, retrieves decide_supplier_payment decisions, nor creates a verification.

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 explicit when-to-use conditions and exclusions: supply the returned verification_id UUID, not request_id, transaction_id, invoice number, or A2A task ID, and the ID must belong to the same tenant. It names the alternative actions (decide_supplier_payment, verify_supplier_payment) it is not a substitute for.

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