Sync My Cycle

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it states the required input ('Needs the first day of their last period'), the medical disclaimer scope, and the `period_may_be_late` output behavior plus its doctor-referral advice. It stops short of describing latency, data sources, or the general return shape.

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?

Front-loads the core purpose, then usage, then exclusions, which is a sound order. It is slightly redundant in re-stating the pregnancy/contraception exclusion twice in one sentence, which costs a little efficiency but does not obscure the message.

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?

For a read-only, no-output-schema tool the description covers purpose, triggers, exclusions, the required input, and one notable output behavior (`period_may_be_late`). An agent has enough to call it correctly; only the broader return structure (kit links, food ideas) is left implicit.

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% and all 8 parameters (tz, date, diet, country, cycle_length, period_length, last_period_start) are documented in the schema with defaults and ranges. The description only reinforces that `last_period` is required, adding no format, unit, or default detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb+resource: returns today's cycle phase along with workout and food ideas, and the title restates it consistently. It is clear what the tool produces, but it never references its siblings get_week_ahead or list_phases, so the agent gets no explicit differentiation from them.

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?

Gives explicit trigger scenarios ('what phase am I in', 'what should I train today?', 'why their energy is up or down') and explicit exclusions ('Not for getting pregnant, fertile days, ovulation timing, contraception or pregnancy'). It even directs those out-of-scope users to a doctor or pharmacist, leaving nothing to inference about when this tool is and isn't appropriate.

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

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuine edge-case behavior beyond that: when `period_may_be_late` is true, `days` is empty and the say line advises a doctor. It does not cover pagination or precision caveats, but for a read-only tool this is solid added context.

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?

Front-loaded with purpose and trigger, which is good, but the exclusion sentence is bloated and self-repeating ('not for pregnancy planning or contraception... it is not a fertility calendar' after already listing pregnancy and contraception). Tighter phrasing would preserve the exclusions with less redundancy.

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 output schema, the description carries the return-shape burden and does name the four returned fields plus the empty-result behavior. It is complete enough to call correctly; only minor gaps remain around how phase prediction degrades when cycle history is short.

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%, so every parameter, including the deprecated `last_period_start` alias and the no-op `diet`, is already documented in the schema. The description adds no parameter syntax or format detail beyond that, which is the correct baseline when the schema does the work.

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 states a specific resource and scope (each day's likely phase, workout focus, intensity and food focus) and implicitly contrasts with get_todays_phase by being the multi-day view. An agent can distinguish it from siblings without opening either schema.

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?

It gives a concrete trigger ('plan training or meals for the week, for example "plan my training this week around my cycle"') plus an explicit exclusion list (pregnancy, fertile days, ovulation timing, contraception) and names the alternative domain. Nothing about when-not-to-use is left to inference.

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

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

Annotations already declare read-only, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds genuinely useful scope boundaries (wellbeing only, not medical/contraception use), though it says nothing about return shape beyond the topic areas.

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 tightly packed sentences with the usage guidance front-loaded after a short purpose statement. The main waste is that the first sentence duplicates the title verbatim rather than adding information.

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?

For a zero-parameter, no-output-schema reference tool, the description covers purpose, routing conditions, and scope exclusions adequately. It could be more complete by noting that all phases are returned at once, but nothing essential is missing.

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 tool takes zero parameters and the schema confirms an empty object, so the baseline is 4. The description correctly offers no parameter detail because none exists.

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 first sentence states the resource (cycle phases) and the content returned: what each phase feels like plus workout and food ideas. It is clear enough to distinguish from the dated siblings, though it never literally says 'list all phases' or names those siblings.

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?

Strong when-to-use guidance: 'For general questions about cycle syncing that need no dates' with a concrete example query, plus an explicit when-not list (conception, fertile days, contraception, pregnancy). It stops short of naming the sibling tools for date-based queries, leaving that routing to inference.

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