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

With no annotations, the description carries the full burden and does well: it discloses the hard x402 requirement, the payment rail (USDC on Base L2 via the x402 facilitator), and the outcome (listing id and review status). It stops short of covering review timelines, failure/rejection behavior, or whether submission is reversible.

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 tight sentences: purpose first, hard requirement second, return value last. No filler, and the gating constraint is front-loaded where it matters most.

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?

The output schema exists, so explaining return values is optional, and prerequisities are well covered. However, for a 6-required-parameter submission tool with 0% schema description coverage, the description leaves the actual arguments entirely unexplained, which is a real completeness 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?

Schema description coverage is 0% for 7 parameters, so the description must compensate but does not. It never explains name, description, endpoint_url, price_per_call, developer_email, payment_address, or the category default, leaving an agent to guess formats such as price units and address encoding.

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 ('Submit an agent to the AgentPayStore marketplace for review'), which cleanly distinguishes it from siblings like marketplace_browse and marketplace_check_endpoint. An agent immediately knows this is the write/listing action rather than a discovery or verification call.

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?

Explicitly states the precondition that x402 compliance is REQUIRED and directs the agent to run marketplace_check_endpoint first to self-verify. It gives a clear when-to-use path but does not spell out when-not to submit or any consequences of a non-compliant submission beyond the requirement itself.

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