explain_cron_expression

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

The description explicitly states that the tool is read-only ('never schedules or executes anything'), which is crucial for behavioral safety. It also mentions supported features (ranges, lists, steps, names). Since no annotations are provided, the description carries the full burden, and it meets it well, though it could elaborate on error handling or invalid input behavior.

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 extremely concise—two sentences that efficiently state purpose, supported features, and a critical behavioral disclaimer. No unnecessary words or repetition.

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?

Given the tool's simplicity (single parameter, no output schema), the description is fairly complete. It explains input and behavior. However, it lacks explicit mention of the return format (plain English string), which could be inferred but is not stated. The sibling tools are similar, and the description provides enough differentiation.

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 has 100% coverage with a description and example for the single parameter. The description adds meaning beyond the schema by specifying that the expression is 'five-field' and supports 'ranges, lists, steps, and month or weekday names,' which guides the agent on valid input patterns.

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 purpose: 'Translate a five-field cron expression into plain English.' It uses a specific verb ('Translate') and resource ('cron expression'), and distinguishes itself from sibling tools like 'validate_cron_expression' (validation) and 'next_cron_occurrences' (computation).

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 provides clear context: it supports ranges, lists, steps, and names, and explicitly states that it 'never schedules or executes anything.' This helps differentiate from tools that might schedule or execute. However, it does not explicitly list when not to use it or name alternatives beyond the negative scheduling statement.

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