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

Annotations already declare idempotentHint=true, readOnlyHint=false, openWorldHint=false. The description goes beyond them by disclosing the mechanism: it replays the same idempotency key with PAYMENT-SIGNATURE server-side, explaining how idempotency and signing are achieved. The final clause about the operator signer is cryptically worded but adds a revenue/ownership caveat.

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?

Three short sentences, front-loaded with the core action and no filler. The closing sentence ('An RQM-owned operator signer is not external revenue') is opaque and its purpose is unclear, a minor structural blemish on an otherwise tight definition.

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?

Return values need not be described given an output schema exists, and annotations cover the safety profile. For a payment-settlement tool the description conveys what it does, when (hosts that cannot sign) and the key mechanism, though the request-variant semantics rest entirely on the schema.

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?

The report lists 0 parameters with 100% schema coverage, so the oneOf challenge/capability structure (idempotency_key, payment_required, capability_id) is already documented in the schema. The description references idempotency-key replay and PAYMENT-SIGNATURE, loosely reinforcing schema concepts, but does not explain the two request variants. Baseline 4 applies for the zero-parameter case.

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 and resource scoped to a niche: 'Server-side Jobs-rail x402 settle'. Combined with the title 'Auto-settle a Jobs buyer 402', an agent can tell this handles payment settlement rather than job execution like run_buyer_job. The heavy acronym/jargon load (x402, RQM, PAYMENT-SIGNATURE) makes intent clear only to a domain-aware reader, keeping it short of a 5.

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?

'for connector hosts that cannot sign' gives a real usage condition, and 'An RQM-owned operator signer is not external revenue' hints at an exclusion. However, no sibling alternative (e.g., run_buyer_job, quote_job) is named and no explicit when-not is given, so routing is only implied.

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