Parse a 5-field cron expression to compute next N run times. Get accurate future schedule dates locally without network calls.
Parse a 5-field cron expression and compute the next N run times
| Name | Required | Description | Default |
|---|---|---|---|
| count | No | Number of future run times to return, default 5 | |
| expression | Yes | Cron expression, e.g. "*/15 9-17 * * 1-5" |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It correctly states the tool handles only 5-field expressions and computes future run times, but it omits timezone assumptions, validation behavior, and whether 'next' is relative to the current moment. Adequate but minimal.
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?
A single, front-loaded sentence that states the action, input scope, and output in a compact way. There is no filler or redundant information.
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 simple pure function with 2 documented parameters, the essential calling information is present. However, with no output schema, the return format (e.g., ISO strings, timestamps, date objects) is not specified, and timezone/validation behavior is unknown. These gaps are noticeable but not blocking.
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 description coverage is 100%, and the schema already documents both expression (with example) and count (with range and default). The description's 'N run times' adds no new parameter-level meaning, so the 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?
The description uses specific verbs 'parse' and 'compute', names the exact resource (a 5-field cron expression), and defines the output (next N run times). It is unambiguous and clearly distinct from sibling utilities like parse_date or convert_timestamp.
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?
No explicit when-to-use guidance or alternative tools are mentioned. The intended context is implied by the purpose, but the description does not state when to prefer it over other utilities. Since no sibling directly overlaps, this is a minor gap.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.