# AgentTools Cron Expression Describer

> AgentTools Cron Expression Describer is a paid API for AI agents from agenttools-hub.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Translates a cron expression into plain English, validates it, and computes the next scheduled execution times

## Facts

- Endpoint: GET https://agenttools-hub.vercel.app/api/v1/dev/cron-describe?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agenttools-cron-expression-describer-87810b43
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kZHwvDYeTddxAZFxgic82

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agenttools-cron-expression-describer-87810b43
```

Example prompt: Can you explain what the cron expression '0 9 * * 1-5' means in plain English and tell me the next 5 times it will fire?

## When to prefer this

Use this endpoint when an agent needs to deterministically explain, validate, or compute next run times for a standard 5-field cron expression without guessing or hallucinating schedule semantics. Prefer this over asking an LLM to interpret cron syntax directly, since LLMs can misread edge cases like day-of-week ranges or step values. Ideal for developer-facing agents, DevOps automation, CI/CD explanation tools, and any workflow that needs to surface human-readable schedule summaries.

## Known failure modes

- Invalid or malformed cron expression returns a validation error
- Missing required 'expr' query parameter results in a 400-level error
- Cron expression with impossible combinations (e.g. Feb 30) may return empty next-run list or validation failure
- Non-standard 6-field or 7-field cron expressions (with seconds or year) may not be supported — only 5-field expressions accepted

## How this service works

Turn a cron expression into plain English, validate it, and compute the exact next execution times. Deterministic — the answer to 'when does this cron actually fire?' without guessing. Use this when an agent needs to explain a cron expression and compute the next runs.

## Output

Returns a plain-English description of the cron schedule, a validation status indicating whether the expression is well-formed, and a list of computed next execution timestamps based on the provided reference date (or current time if none given).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "expr"
     ],
     "properties": {
      "ref": {
       "type": "string",
       "description": "Reference date (optional)"
      },
      "expr": {
       "type": "string",
       "description": "5 fields: minute hour day month weekday"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agenttools-cron-expression-describer-87810b43/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agenttools-hub.vercel.app](https://www.zero.xyz/host/agenttools-hub.vercel.app/llms.txt)