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

The description says 'Idempotent on (quoteId, occurredAtIso)' while the annotation idempotentHint=false — a direct contradiction. Per the rubric, this forces a score of 1 even though the description otherwise discloses scaffolding status and auth failure mode.

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-loaded with the core operation; the idempotency, scaffolding, and auth details are all decision-relevant. The text is longer than average, but each section carries operational payload; minor issue numbers and the read-tier note are near misses but not padding.

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?

Coverage of lifecycle, idempotency, scaffold state, and auth is strong for a no-output-schema tool, and the degraded response is shown. However, the successful response shape is never disclosed, and several parameters remain unexplained. An agent can call it but cannot fully predict the success/error contract beyond auth and scaffolding.

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 0%, so the burden falls on the description. It names the eventType enum and identifies (quoteId, occurredAtIso) as the idempotency key, but gives no explanation of lenderId, merchantId, amountUsdCents, evidence, or agentBearer; agentBearer especially is left opaque. Only partial compensation for a six-required-parameter tool.

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?

Opens with 'Record a repayment event (PAID / PARTIAL / MISSED) against a previously-issued credit quote' — a specific action, target, and value set. It clearly distinguishes itself from verify_repayment_history by describing itself as the Schema D writer and the sibling as the reader.

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 places the tool in its lifecycle: it is a writer that persists events and anchors attestations, while the sibling verify_repayment_history is the reader. The AUTH note draws a clear read/write boundary: write calls require a key, reads do not. It does not spell out an explicit 'use verify_repayment_history instead when...' exclusion, so it misses the top bar.

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