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

Rich disclosure beyond annotations: per-venue proof of presence, the queued-and-later-submitted semantics, that human-gated venues are never charged, that venue-side fees surface as 'unfunded' and are never fronted, and that the order is rechecked weekly for 90 days. The only thing not stated is what happens on expiry beyond 'rechecked', and the 'no account, no API key' claim adds auth context the annotations do not carry. No conflict with readOnlyHint=false or destructiveHint=false.

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 'PAID:' and packed with useful facts, but the final sentence about POST /feedback ('Complaints, questions, quote requests...') is a tangent for a submission tool and saps density. Several sentences chain three or four clauses together, making the payment protocol harder to scan than it needs to be.

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?

With no output schema, the description still tells the agent where the result appears (per-venue proofs, _meta['x402/payment-response'] receipt) and what the intermediate states mean (queued, unfunded, human-gated). For a payment-gated mutation with two optional params, nothing an agent needs 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 coverage is 100% and both parameters are already documented there, so the schema does the heavy lifting. The description adds only the extension rule tied to a repeated url, which is a genuine behavioural nuance but small. 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 and resource ('we submit your service to every permissionless agent venue') and scopes it precisely ('17 of the 33 on-behalf venues today'), plus names the siblings placement_status and placement_cancel for reading back and stopping. An agent can distinguish this from placement_venues, placement_ready, and listing_promote without opening any schema.

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 an explicit call protocol: call once without payment to receive the x402 PaymentRequired, call again with a signed payment in _meta['x402/payment'] to complete. It also names the alternatives ('Read it back with placement_status, stop it with placement_cancel') and states the re-pay behaviour (extension, not a second order).

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