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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so safety and idempotence are covered. The description adds the important scope boundary (general wellbeing only, not medical/pregnancy/contraception advice), which is valuable behavioral context. It does not describe the output format or prohibitive medical disclaimers beyond scope, keeping it at 3.

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?

Two sentences plus an example, front-loaded with the tool's purpose and then scope. The example is helpful and earns its place, but the title repetition slightly pads the opening. Efficient overall.

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 no parameters, no output schema, and rich annotations, the description is nearly complete: it explains purpose, when to use, and exclusions. It could be improved by mentioning how to obtain phase-specific advice (e.g., invoking a phase argument). Adequate but not exhaustive.

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?

With 0 parameters, the baseline is 4. Schema is empty and the description appropriately doesn't invent parameters, correctly indicating a parameterless, prompt-based tool. No further parameter semantics are needed.

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 what the tool does via the title ('What each phase usually feels like, with workout and food ideas') and a concrete example ('what should I eat in my luteal phase?'). It distinguishes itself from siblings by being the no-dates general-information tool, implicitly contrasting with syncmycycle_get_todays_phase and syncmycycle_get_week_ahead. Not a full 5 because the core verb is somewhat buried in the title rather than the body.

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?

Provides a specific usage condition: 'For general questions about cycle syncing that need no dates.' It also lists clear exclusions ('Not for conception, fertile days, contraception or pregnancy'). Missing is explicit routing to the sibling tools for date-specific or phase-dated queries, so 4 rather than 5.

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