explain_cron

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

With no annotations provided, the description fully carries the behavioral disclosure burden. It includes a comprehensive 'Behavioral Transparency' section covering side effects (read-only, stateless), authentication (no auth for basic usage), rate limits (10/day free), error handling (structured errors), idempotency (fully idempotent), and data privacy. This exceeds typical detail and aligns with the tool's safety profile.

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 well-structured with clear sections (Behavior, When to use, Args, Behavioral Transparency), but it suffers from redundancy. The 'Behavior' section and the 'Behavioral Transparency' section repeat nearly identical information about read-only, stateless, idempotency, rate limits, and authentication. This could be streamlined without loss of meaning.

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 tool that explains cron expressions, the description provides extensive behavioral context but does not mention the output format. However, context signals indicate an output schema exists, so the agent can use that for structure. Given the tool's moderate complexity, the description is largely complete, though a brief note on output would strengthen it.

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 0%, so the description must compensate. However, the 'Args' section provides minimal and misleading information. 'expression' is described as 'The expression to analyze or process'—vague and failing to specify it's a cron expression. 'api_key' is described identically as 'to analyze or process', which is incorrect; its role is authentication. The description adds little semantic value beyond the parameter names.

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: 'Explain a cron expression in human-readable English.' This is a specific verb+resource combination. Sibling tools (generate_cron, next_runs, parse_cron) have distinct purposes, and the description implicitly differentiates by focusing on explanation rather than generation, prediction, or parsing.

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 includes 'When to use' and 'When NOT to use' sections, providing context on appropriate scenarios (structured analysis) and exclusions (not for real-time decisions without human review). However, it does not explicitly mention alternative sibling tools for specific cases, leaving the agent to infer distinctions from the tool name and purpose.

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