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

No annotations are provided, so the description must carry the full behavioral burden. It discloses the returned shape (decision, reason, evidence references), which is genuinely useful given there is no output schema, but it says nothing about failure modes for an unknown txId, permissions, or whether the decision record can change after the fact.

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?

A single well-formed sentence with zero waste; the purpose and the returned fields are front-loaded before the keying detail.

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 one-parameter read tool with no output schema, the description covers what comes back and where the id originates, which is most of what an agent needs. It omits what happens when the txId is unknown or unauthorized, leaving a small gap.

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?

One parameter at 100% schema description coverage, so the schema already documents txId fully, including its provenance from x402shield_authorize_payment. The description repeats that provenance without adding format or validation meaning beyond the schema, matching the baseline 3.

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 ('Look up') and resource ('the recorded decision, reason and evidence references') and ties the lookup key back to the sibling that produced it (x402shield_authorize_payment). It distinguishes itself from the sibling that creates the record, though it does not explicitly separate itself from x402shield_get_evidence, which also returns evidence references.

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?

Clear usage context: this is for payments 'previously checked with x402shield_authorize_payment', implying it is a follow-up read rather than a first action. No explicit when-not or exclusions are given, so it stops 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.