12-point cold email score with concrete fixes Free check: https://sigtap-outreach-api.sigtap.workers.dev/preview/grade = 200 demo sample, no wallet. Paid call: 402 challenge -> sign -> retry = settled on-chain. ($0.005 USDC on Base, x402)
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | Plain-text email body | |
| subject | Yes | Email subject line |
| Name | Required | Description | Default |
|---|---|---|---|
| grade | Yes | ||
| score | Yes | ||
| checks | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "checks": {
+ "items": {
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "grade": {
+ "type": "string"
+ },
+ "score": {
+ "type": "number"
+ }
+ },
+ "required": [
+ "score",
+ "grade",
+ "checks"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description is transparent about the payment requirement, wallet interaction, and on-chain settlement via x402 on Base. It also clarifies that the free check is a demo sample, so users are not misled about costs or side effects.
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 compact and information-dense, covering scoring, fixes, demo access, and payment details without unnecessary fluff. The flow is compressed into a few phrases but remains understandable.
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 provides enough context for a user to decide whether to try the free sample or proceed with the paid call. It includes pricing, protocol, and the auth flow, making the tool's operational context reasonably complete.
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 input schema already provides clear descriptions for 'subject' and 'body', so the tool description adds no additional meaning beyond those field names. The parameter semantics are adequately covered by the schema itself.
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 clearly states the tool's purpose: providing a 12-point cold email score with concrete fixes. It identifies the resource (cold email) and the action (scoring) with enough specificity, though it does not explicitly distinguish itself from sibling tools.
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 concrete usage guidance by explaining both the free demo endpoint and the paid call flow (402 challenge -> sign -> retry). It tells users how to access the tool and what to expect financially, which is practical and actionable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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