x402.networksList supported settlement networks, facilitators, and x402 v2 header names. Call when choosing a preferred_network for x402.pay_and_fetch or x402.build_seller.
| Name | Required | Description | Default |
|---|---|---|---|
| agent_id | No | Optional agent identity for quota accounting. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint = true, idempotentHint = true, and destructiveHint = false, and the description does not contradict these. It adds meaningful behavior details by stating the tool also returns facilitators and x402 v2 header names, not just a simple network list. This gives the agent a better sense of what will be present in the response before calling.
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?
Two-short sentences carry all the necessary information with no filler. The first sentence states the output scope, and the second sentence orients the selection toward the tools that consume a preferred_network.
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 simple, read-only, no-required-parameter lookup tool with an output schema, the description provides adequate use-case information and behavior visibility. It might mention what to do after picking a network, but that is not necessary for calling the tool correctly.
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 only parameter agent_id is already fully described in the schema as an optional agent identity for quota accounting, so schema coverage is 100%. The description does not need to repeat the parameter semantics and generally does not add value beyond the schema for this single parameter; a 3 is the appropriate baseline.
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?
The description uses a specific verb ('List') and names the exact resources: supported settlement networks, facilitators, and x402 v2 header names. It clearly identifies what the agent will learn from the tool. It references the paying/building siblings that consume a preferred_network, but it does not explicitly distinguish from every possible sibling such as x402.discover.
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 gives a concrete usage cue: call when choosing a prefferred_network for x402.pay_and_fetch or x402.build_seller. This is clear context for when the tool is useful, though it does not explicitly state when not to use it or name an alternative lookup tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The namespaces help, but there is real overlap in purpose: city.check with x402.pay_and_fetch, city.sample with x402.probe, and multiple tools that verify a payment and then activate, credit, or settle something. The descriptions clarify which resource is being paid for, but tool names alone leave room for misselection.
Nearly every tool uses a lower-case dotted namespace.action pattern, making the set easy to scan. Some command parts are inconsistent, though: x402.networks, pulse.base, and commerce.credits_requirements read as nouns rather than actions, so the style is mostly but not fully uniform.
Nineteen tools is in the heavy range, and they span many subsystems: x402, city, commerce/quotas, swarm, ops, and Base network metrics. The number is not extreme, but the server feels like multiple product surfaces bundled under one MCP rather than a tightly scoped toolset.
The x402 lifecycle is well covered: discover, probe, pay, fetch, verify, sell, and settle, plus supportive commerce and city workflows. Notable gaps are refunds/quota-balance checks, seller resource update/removal, and invoice-like management for Stripe/card purchases, but none blocks the object workflows.