Free. Compare a live primary x402 quote with your saved baseline; detect price, network, asset, recipient and HTTP status changes. No payments sent; no uptime-history claim.
| Name | Required | Description | Default |
|---|---|---|---|
| request | Yes |
Changes observed during successful MCP inspections.
Input schema / properties / max_charge_atomicRemoved value: -{
- "anyOf": [
- {
- "type": "string"
- },
- {
- "type": "null"
- }
- ],
- "default": null,
- "title": "Max Charge Atomic"
-}Input schema / properties / operation_idRemoved value: -{
- "anyOf": [
- {
- "type": "string"
- },
- {
- "type": "null"
- }
- ],
- "default": null,
- "title": "Operation Id"
-}Input schema / properties / operation_idAdded value: +{
+ "anyOf": [
+ {
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "default": null,
+ "title": "Operation Id"
+}Input schema / properties / max_charge_atomicAdded value: +{
+ "anyOf": [
+ {
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "default": null,
+ "title": "Max Charge Atomic"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the bar is lower. The description adds real behavioral context beyond them: it is free (no cost), sends no payments, and explicitly disclaims uptime-history, which prevents a common misreading of the tool's scope.
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 the cost signal ('Free.') and two tight semicolon-separated clauses plus a scope-limiting closer. Every clause carries information; nothing is padded, though the final disclaimers could arguably be folded tighter.
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 read-only comparison tool with no output schema, the description enumerates the change categories it detects (price, network, asset, recipient, HTTP status), which is an adequate proxy for return content, and disclaims what it does not cover. Only the request url/method handling remains unstated.
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%, so the description carries the burden, yet it only explains the 'baseline' concept ('your saved baseline') and leaves url and method semantics untouched. The baseline mention is genuinely useful but does not fully compensate for the coverage gap.
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 pair (compare, detect) and a specific resource (live primary x402 quote vs saved baseline), plus the exact dimensions checked (price, network, asset, recipient, HTTP status). It is distinguishable from x402_health_check via the 'no uptime-history claim' boundary, though it never names that sibling.
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 phrase 'with your saved baseline' implies the prerequisite (you must already hold a baseline), and the 'no payments sent / no uptime-history' notes bound the scope. However, there is no explicit when-to-use vs alternatives guidance or statement of what to do when no baseline exists.
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.