v1_budget_preflightChecks whether a proposed agent action amount complies with a budget policy before spending, enabling preflight approval decisions for paid x402 routes.
Budget Preflight
Remote route: POST /v1/budget/preflight (0.25 USD x402/base/usdc on eip155:8453).
| Name | Required | Description | Default |
|---|---|---|---|
| policy | No | ||
| agent_id | No | ||
| action_amount_usd | No |
| Name | Required | Description | Default |
|---|---|---|---|
| status | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds useful behavioral context beyond the annotations by disclosing the POST route and a specific x402/USDC cost. However, it does not explain authorization requirements, side effects, or what the preflight validates, even though annotations mark it non-read-only and open-world.
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?
The text is short but under-specified, and the first line merely repeats the title. The route and pricing sentence is useful, but the overall structure does not front-load the tool's actual function.
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?
Although an output schema exists and annotations provide safety hints, the description omits the tool's core behavior, parameter semantics, and usage guidance. For a three-parameter paid endpoint, this is not enough for an agent to invoke it confidently.
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%, and the description provides no meaning for the three parameters (policy, agent_id, action_amount_usd). The parameter names alone are not enough to compensate for the complete lack of schema documentation.
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 essentially restates the tool name/title, 'Budget Preflight,' and adds only a remote route and price. It does not state what a budget preflight actually checks or returns, so an agent cannot distinguish its purpose from siblings such as v1_quota_preflight or v1_agent_preflight.
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?
There is no guidance on when to use this tool, what prerequisites exist, or which sibling tool should be used instead. The description only provides transport and pricing details, leaving usage context entirely implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.