Paid full research brief (0.02 USDC Base · upgrade). Free first: x402_sample_outline; optional outline 0.01 first. Body {topic}. Without paymentHeader returns 402 + accepts[].
| Name | Required | Description | Default |
|---|---|---|---|
| topic | Yes | Topic or https URL | |
| paymentHeader | No | Optional X-PAYMENT proof after settling USDC |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behaviors. It mentions the payment requirement and the consequence of missing paymentHeader (returns 402 with accepts array). However, it does not describe the success response format, rate limits, or authentication needs, leaving 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?
The description is very short (35 words) and front-loads the key point. However, it uses cryptic formatting (e.g., '0.02 USDC Base · upgrade') and lacks clear sentences. While concise, it sacrifices readability for brevity.
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 description does not explain the output of a successful call (e.g., format of the research brief). Given no output schema and no annotations, more context is needed on the response structure and the payment flow. The 402 error case is mentioned but the success case is omitted.
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%, so parameters are already documented. The description adds value by clarifying that without paymentHeader the tool returns a 402 error, and that topic should be placed in the request body ('Body {topic}'). This gives practical usage context beyond the schema.
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 states 'Paid full research brief' indicating the tool generates a comprehensive research brief for a fee. It distinguishes from sibling tools like x402_sample_outline by implying this is the paid full version. However, the meaning of 'research brief' is not explicitly defined.
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 mentions alternatives: 'Free first: x402_sample_outline' and 'optional outline 0.01 first' (likely x402_research_outline). This gives guidance on when to use which tool based on cost. However, it could be clearer about the exact conditions.
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.
Each tool has a distinct primary purpose (discovery, health, free sample, paid outline, paid brief, alternative scrub), but the conversion ladder is mentioned in multiple tools, which could cause slight confusion for an agent about which free tool leads where.
All tools consistently use the 'x402_' prefix followed by a descriptive compound noun (e.g., discovery, health, research_brief, sample_outline), creating a predictable and clear naming pattern.
With 6 tools, the set is well-scoped for a research API with a free-to-paid conversion ladder, covering all necessary stages without superfluous or missing tools.
The tools cover the complete research generation flow (discovery, health check, free sample, paid outline, paid brief), with an alternative scrub demo. A minor gap is the absence of a history or status tool for previously generated research.
