cron_explain

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

With no annotations provided, the description carries the full burden. It discloses the core behavior (explain in plain English and show next 5 run times) but lacks additional context such as timezone handling, error behavior for invalid expressions, or whether the next run times are relative to the current time. These are notable but not critical gaps for a simple utility.

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?

The description is a single, compact sentence that conveys both the primary action and the expected output. It is front-loaded and contains no filler or redundant information, making it highly efficient and easy to parse.

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 single-parameter tool with no output schema or annotations, the description provides most of the needed context: what it does and what it returns. Missing details like timezone and error handling are minor for typical use, so it is nearly complete for the tool's complexity.

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?

The schema already provides 100% coverage for the only parameter, describing it as 'Cron expression (5 fields: minute hour day month weekday)'. The description adds no further information about the parameter, so the baseline score of 3 applies when schema coverage is high.

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 clearly states the tool's function: 'Explain a cron expression in plain English and show the next 5 run times'. It uses a specific verb ('explain') and resource ('cron expression'), and the 'show next 5 run times' adds concrete scope, distinguishing it from sibling utilities which focus on other unrelated operations.

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?

The description implies the tool is used for interpreting cron expressions, but provides no explicit guidance on when to use it versus alternatives, nor any conditions or exclusions. It does not mention related tools or scenarios where it would not be appropriate.

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