Parses a 5-field cron expression, explains it in English and lists the next run times in a time zone. 0.001 USDC per call via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| tz | No | IANA time zone | UTC |
| cron | Yes | Cron expression, e.g. */15 9-17 * * 1-5 | |
| count | No | ||
| paymentProof | No | Payment proof: USDC tx hash on Polygon or Base (0x...) or Solana tx signature. Omit on the first call to receive the 402 payment instructions, pay, then call again with the proof. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the full behavioral burden. It usefully discloses the per-call cost and the paid-call model via x402, but says nothing about behavior on invalid cron expressions, what the English explanation looks like, or whether counts are capped.
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 short sentences, the functional core front-loaded and pricing appended. Zero wasted words.
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 4-parameter utility with no output schema, the definition covers purpose, scope, and cost adequately; the payment retry semantics live in the schema. Only minor gaps remain: invalid-input behavior and the count parameter's effect.
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 75% and the schema documents tz and paymentProof well. The description reinforces the time zone and 5-field aspects but adds nothing about the count parameter or the payment-proof retry flow beyond what the schema already states. Baseline 3 applies.
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?
Three specific verbs (parses, explains, lists next run times) applied to a specific resource (5-field cron expression) with a time zone scope. No sibling is remotely similar, so an agent can select it unambiguously.
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?
Purpose strongly implies when to use it, but there is no explicit when/when-not guidance or mention of alternatives, and the payment flow ('0.001 USDC per call via x402') is stated as a fact rather than as a usage consideration.
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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