next_runs

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

With no annotations, the description bears the full transparency burden. It indicates a non-mutating 'calculation' behavior, but it does not disclose details such as timezone handling, behavior with invalid cron expressions, or whether the count starts from the current time. This leaves some ambiguity about edge-case 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 a single, front-loaded sentence with no unnecessary words. It states the core action and object clearly, making it maximally concise while remaining informative.

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?

The tool is simple, and an output schema is present, so the description does not need to explain return values. The core function is well captured. However, it lacks any mention of how this tool relates to sibling cron tools, such as when to use it instead of validators or log viewers, so it is not fully complete.

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% because both 'expression' and 'count' have descriptions. The tool description adds little beyond the schema, only indirectly relating 'N' to the count parameter via the phrase 'next N execution times'. Baseline of 3 is appropriate given full schema coverage.

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 the specific verb 'calculate' and identifies the exact resource ('next N execution times for a cron expression'). This clearly differentiates it from sibling tools like validate_cron_expression and explain_cron_expression, which serve different purposes.

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 usage when one needs to compute future run times of a cron expression, but it does not explicitly state when to prefer this tool over siblings, nor does it mention any exclusions or alternatives. Guidance remains implied rather than explicit.

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