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

No annotations are provided; the description merely states the operation and return format without disclosing assumptions (e.g., average luteal phase length), edge cases, or precision. This is insufficient for a calculation tool.

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 two sentences, each serving a clear purpose: stating the calculation and pointing to related tools. No wasted words.

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?

With no annotations and no explicit output schema, the description lacks details on calculation methodology, assumptions, and error handling. For a menstrual cycle calculator, this is incomplete.

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 covers both parameters with descriptions. The description adds value by specifying the output structure, but does not enhance parameter meaning beyond what the schema already provides.

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 calculates next period, fertile window, and ovulation date, and lists the return fields. This distinguishes it from many sibling calculators, though it doesn't explicitly differentiate from the similar 'calculate_ovulation' tool.

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?

Only a brief reference to 'see list_bundles for related calculators' is provided, with no explicit guidance on when to use this tool versus alternatives like 'calculate_ovulation' or other fertility-related tools.

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