List the x402 services discovery catalog's active edge, liveness-probed: know a service is up and correctly demanding payment before you pay it. Free; up to 25. For the full liveness-probed feed use get_x402_services_snapshot (paid, x402).
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | max results 1-25 (default 10) | |
| payable_only | No | only services currently returning 402 (payable right now) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses liveness-probing behavior, the guarantee that services are up and demanding payment, and the free limit of 25. It implies read-only nature via 'list' and 'before you pay it', but does not mention sorting or response format, leaving some minor gaps.
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 sentences, front-loaded with action and purpose, ending with alternative tool reference. Every clause adds value without waste.
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?
Simple tool with two optional params and no output schema; description covers purpose, constraints (free, max 25), behavioral guarantee (liveness-probed), and alternative for full feed. Minor gap: no mention of return shape or default order, but sufficient for basic use.
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% for both optional parameters (limit and payable_only) with descriptions. The description adds the 'up to 25' cap which aligns with limit's maximum, but provides no additional semantic detail beyond what the schema already states.
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?
Description uses specific verb 'List' and names the resource as 'x402 services discovery catalog's active edge, liveness-probed'. It clearly distinguishes from sibling get_x402_services_snapshot by noting the free/paid split and feed scope.
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 recommends get_x402_services_snapshot for the full liveness-probed feed, and states this tool is free with up to 25 results, giving clear when-to-use and when-not-to-use guidance. This directly addresses alternatives among siblings.
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.
Every tool has a clearly distinct purpose: free vs. paid, list vs. snapshot, search vs. verify, and the standalone risk assessment. Even the similar verification tools are differentiated by 'preview' versus 'full report', leaving no ambiguity.
Most tools follow a consistent verb_noun pattern (get_, list_, search_, verify_, assess_). The only outlier is 'feeds_status', which uses a noun phrase instead of a verb-led form, creating a minor inconsistency.
With 10 tools, the server is well-scoped for its dual purpose of MCP registry access and x402 services. Each tool adds distinct value, and the count comfortably fits the typical 3-15 range without feeling bloated or thin.
The tool set covers the full read-only lifecycle for both feeds: free search, paid full snapshots, delta changes, trending highlights, per-server verification (preview and full), live service listing, and aggregate status. No obvious dead ends for the stated purpose.