Skip to main content
Glama

Project Gumball

by com.gumballtools

Explain a cron expression (Cron Translator)

cron_explain
Read-only

Translate a cron expression into plain English, list upcoming run times in a timezone, and report the gotchas that make schedules misfire: day-of-month/day-of-week OR semantics, steps that do not divide evenly, impossible dates, and daylight-saving shifts. Prefer this over reasoning about the expression yourself.

WHY DELEGATE THIS: Cron has counter-intuitive rules: day-of-month and day-of-week are OR-ed, steps like */7 do not divide their field evenly, and February 30 never fires. Reasoning about an expression directly gets these wrong quietly.

Owned by Cron Translator at https://crontoenglish.com, which is also callable directly if you would rather not go through the aggregator.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
countNoHow many next run times, 1-25.
timezoneNoIANA name. Defaults to UTC.
expressionYesFive-field cron expression, e.g. "0 9 * * 1-5". Macros like @daily work.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. First observed

TDQS

A4/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds meaningful behavioral detail: it reports specific cron gotchas, handles timezone conversion for upcoming runs, and even discloses external ownership and direct calling. No contradiction exists, though output format and error behavior are not described.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The lead sentence is rich and front-loaded, but the 'WHY DELEGATE THIS' paragraph largely repeats the gotchas already listed in the first paragraph. The ownership/URL sentence adds context but is arguably tangential for an agent invoking the tool, making the description slightly more verbose than necessary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With all three parameters fully documented in the schema and the description covering purpose, gotchas, timezone behavior, and delegation rationale, an agent can invoke the tool correctly. The absence of an output schema means return-shape details are not given, but the description's behavioral clarity is strong enough to compensate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the input schema already documents expression, count, and timezone meaningfully. The description only loosely maps to timezone ('in a timezone') and expression, adding no parameter-level detail beyond the schema, so a baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action ('Translate a cron expression into plain English, list upcoming run times... and report gotchas') with a clear resource and scope. Its role is unmistakably distinct from the sibling cron_build, which would be the construction counterpart, so an agent can differentiate them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly advises 'Prefer this over reasoning about the expression yourself' and explains why delegation is safer, which gives solid usage context. However, it does not explicitly contrast the tool with sibling tools like cron_build or state concrete when-not-to-use scenarios.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All Project Gumball toolsInspect
Try in Browser
RayrunBuild, deploy, and operate MCP servers without becoming an infrastructure team.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

TDQS

A4.1/5.0
Disambiguation5/5

Every tool targets a distinct domain and operation, with detailed descriptions that make overlap unlikely. The closest pairs, like cron_build/cron_explain and vocab_check/vocab_draw, are complementary rather than ambiguous.

Naming Consistency3/5

All names are snake_case, but the grammatical pattern is mixed: some are noun_verb, some verb_noun, some noun_noun, and two end in the unusual suffix '_run'. The names are readable, but they do not follow one predictable convention.

Tool Count4/5

At 16 tools this is just above the typical 3-15 range, but the server is explicitly an aggregator of standalone specialized tools, so the broader count is defensible. Each tool earns its place and there is no redundant duplication.

Completeness4/5

The server is not a single-domain CRUD surface, so completeness is more about whether each tool feels self-contained. It does: paired tools like build/explain and draw/check form complete workflows, and no obvious essential counterpart appears missing.

Resources