Cron Parser Skill

OnlineCredit Usage:1 per callTool:CronParserSkill

The tool

Cron Expression Parser analyzes cron expressions to provide detailed breakdowns of timing, validation results, and human-readable descriptions of when tasks will run.

Once your client is connected to the VerveKit MCP server, this appears in its tool list as CronParserSkill. It is read-only and open-world: it fetches, it never mutates anything on your side, so most clients will call it without asking you to confirm.

Tool call

{
  "name": "CronParserSkill",
  "arguments": {
    "expression": "0 9 * * 1-5"
  }
}

What that looks like in a conversation

You don't name the tool — the model picks it. Asking about 0 9 * * 1-5 in the terms this source covers is enough for it to reach for CronParserSkill on its own.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth — the client opens a browser once and there is no key to paste into a config file.

Client config

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Endpoint

https://api.vervekit.com/v1/mcp

Per-client setup — Claude Desktop, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made.

Argument	Type	Example	Description
`expression`Required	string	`0 9 * * 1-5`	The cron expression to parse (5-field or 6-field format)

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client can read fields without parsing prose. status is "ok" on success and error is null; a null field means the value wasn't available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "expression": "0 9 * * 1-5",
    "isValid": true,
    "format": "5-field",
    "fields": {
      "second": {
        "expression": "0",
        "description": "At 0",
        "values": [
          0
        ]
      },
      "minute": {
        "expression": "0",
        "description": "At 0",
        "values": [
          0
        ]
      },
      "hour": {
        "expression": "9",
        "description": "At 9",
        "values": [
          9
        ]
      },
      "dayOfMonth": {
        "expression": "*",
        "description": "Every",
        "values": [
          1,
          2,
          3,
          4,
          5,
          6,
          7,
          8,
          9,
          10,
          11,
          12,
          13,
          14,
          15,
          16,
          17,
          18,
          19,
          20,
          21,
          22,
          23,
          24,
          25,
          26,
          27,

Fields

Fields marked Premium need a paid plan. On a plan without them the key is absent rather than wrong, so a model never reasons over a substituted value.

Field	Type	Example	Description
`expression`	string	`0 9 * * 1-5`	The original cron expression submitted for parsing
`isValid`	boolean	`true`	Whether the cron expression is valid and syntactically correct
`format`	string	`5-field`	Cron format type (5-field or 6-field with optional seconds)
`fields`Premium	object	`{…}`	Detailed breakdown of each cron field with expression and values
`fields.second`Premium	object	`{…}`	The seconds field, its description and the seconds it fires on
`fields.second.expression`	string	`0`	The second field cron expression (0-59 or special)
`fields.second.description`	string	`At 0`	Human-readable description of second field timing
`fields.second.values`	array	`[0]`	Array of valid second values matching the expression
`fields.minute`Premium	object	`{…}`	The minutes field, its description and the minutes it fires on
`fields.minute.expression`	string	`0`	The minute field cron expression (0-59 or special)
`fields.minute.description`	string	`At 0`	Human-readable description of minute field timing
`fields.minute.values`	array	`[0]`	Array of valid minute values matching the expression
`fields.hour`Premium	object	`{…}`	The hours field, its description and the hours it fires on
`fields.hour.expression`	string	`9`	The hour field cron expression (0-23 or special)
`fields.hour.description`	string	`At 9`	Human-readable description of hour field timing
`fields.hour.values`	array	`[9]`	Array of valid hour values matching the expression
`fields.dayOfMonth`Premium	object	`{…}`	The day-of-month field, its description and the days it fires on
`fields.dayOfMonth.expression`	string	`*`	The day of month field cron expression (1-31 or special)
`fields.dayOfMonth.description`	string	`Every`	Human-readable description of day of month timing
`fields.dayOfMonth.values`	array	`[1,2,3]`	Array of valid day values matching the expression
`fields.month`Premium	object	`{…}`	The month field, its description and the months it fires on
`fields.month.expression`	string	`*`	The month field cron expression (1-12 or special)
`fields.month.description`	string	`Every`	Human-readable description of month field timing
`fields.month.values`	array	`[1,2,3]`	Array of valid month values matching the expression
`fields.dayOfWeek`Premium	object	`{…}`	The day-of-week field, its description and the days it fires on
`fields.dayOfWeek.expression`	string	`1-5`	The day of week field cron expression (0-6 or special)
`fields.dayOfWeek.description`	string	`From 1 to 5`	Human-readable description of day of week timing
`fields.dayOfWeek.values`	array	`[1,2,3]`	Array of valid day values matching the expression
`description`	string	`At 9:00 AM on Monday, Tuesday, Wednesday, Thursday, Friday`	Human-readable description of when cron will execute
`frequency`	object	`{…}`	How often the schedule fires, as a type and interval
`frequency.type`Premium	string	`Daily`	Frequency type (e.g., Daily, Weekly, Monthly, Hourly)
`frequency.interval`Premium	string	`day`	Frequency interval unit (day, week, month, hour, minute)
`nextRuns`	array	`["2026-02-19T09:00:00.000Z","2026-02-20T09:00:00.000Z","2026-02-21T09:00:00.000Z"]`	Next 5 scheduled execution times in ISO 8601 format

Failure modes

Errors come back as tool errors with a sentence the model can act on, not a bare status code.

Status	What it means
`400 / 422`	The arguments didn't validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Out of credits. Not a bad key — the month's allowance is spent.
`404`	This skill isn't part of VerveKit. Check the catalog.
`429`	Brief rate limit. Retrying after a moment succeeds.

Other ways to use Cron Parser Skill

Set up Cron Parser Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an X-API-Key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Frequently asked questions

Do I have to tell the agent to use CronParserSkill?

No. The tool's name and description are in the model's context once the server is connected, so it selects the tool when the question calls for it. Naming it explicitly works too and is useful when you want to force the call.

Does connecting the server expose every tool at once?

Yes — one connection lists the whole VerveKit catalog. Clients with a tool budget can usually filter the list; the credit cost is per call, so an unused tool costs nothing.

What does a call cost?

1 credit each time the tool actually runs. A model that reasons about the tool without calling it costs nothing.

Is there a REST version of this?

Yes — the same source is available as a plain HTTPS endpoint on APIVerve, linked above. Same data, same credits, same account.

What's Next?

Continue your journey with these recommended resources

Browse all skills

The full catalog for this door

Connect a client

Claude, Cursor, VS Code and the rest

Plans & credits

What a call costs and how usage resets

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