Cycle irregularity check

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

With no annotations, the description carries full burden. It discloses the heuristic nature (stdev/CV/max-length), input requirements, and clinical disclaimer. However, it does not specify the exact output format (e.g., string vs. JSON), missing some transparency.

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 three sentences: version/purpose, usage guidance, disclaimer. Every sentence adds essential information, no fluff. Front-loaded with version then purpose, efficient.

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 simple tool (1 param, no output schema), the description provides purpose, usage, parameter guidance, and disclaimer. It is nearly complete for an agent to use properly, though omitting exact return format is a minor gap.

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 coverage is 100% for the single parameter, but the description adds value by explaining the need for 3+ cycles and the 'log more periods' recommendation for fewer inputs. This goes beyond the schema's generic description.

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: it reports regularity of cycles based on a heuristic (stdev/CV/max-length). The verb 'reports' and resource 'cycle irregularity' are specific. It distinguishes from siblings by noting it is a gatekeeper before setting 'cycle_irregular: true' on other tools.

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 explicitly says to use this tool before deciding to set cycle_irregular on other tools. It also states input requirements (3+ cycles) and behavior for fewer inputs ('log more periods recommendation'). It includes a disclaimer about not being clinical diagnosis, guiding appropriate use.

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