Cycle predict next period

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

With no annotations, the description carries full behavioral burden. It discloses that cycle_irregular mode widens accepted cycle range and caps confidence at 'low', and notes version v0.3.3. However, it omits other behaviors such as error handling, data requirements (e.g., minimum history length), or whether the tool is read-only.

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 concise sentences, front-loading the core purpose. Every word adds value; no redundancy or fluff.

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 has 2 parameters and no output schema, the description explains the return values (average cycle length, next date, confidence) and the irregular mode. However, it lacks usage context like minimum data requirements, error conditions, or how results should be interpreted, making it only moderately 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 coverage is 50% (only cycle_irregular described). The description adds context for the history parameter by stating 'Given period history' but does not elaborate on its structure beyond what the schema already defines (array of objects with start_date and optional length_days). It partially compensates but not fully.

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 predicts the next period start date using period history, with specific verb 'predicts' and resource 'period history'. It differentiates from siblings like cycle_estimate_phase by focusing on prediction rather than phase estimation, though no explicit differentiation is given.

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 use when period history is available to predict the next period. It mentions the cycle_irregular flag for PCOS patterns but does not provide explicit when-not-to-use guidance or alternatives (e.g., cycle_irregular_check for irregularity assessment).

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