Sleep cycle calculator

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it discloses what the response contains (bedtimes for 6/5/4/3 cycles, plus nap alarms at 20/30/60 min and one full cycle when mode is bed/now) and the configurable cycle/fall-asleep ranges, which is important because there is no output schema.

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?

One dense paragraph with the purpose front-loaded and no filler; every clause carries information (modes, defaults, output variants, clock format). It is run-on and could be split into two or three scannable sentences, which keeps it from a 5.

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-value burden and does so by enumerating the bedtime/wake-time/nap-alarm lists and the clock format. Combined with the parameter defaults it is nearly complete; only minor details (timezone/server-clock assumptions for mode 'now') are 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%, so every parameter including the mode enum, HH:MM pattern, clock enum and both numeric ranges is already documented. The description restates the 90-minute and 15-minute defaults and adds the mode-dependent nap-alarm output, but supplies no new syntax or constraint information beyond the schema; 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?

The first clause names a specific verb and resource — compute sleep-cycle-aligned bedtimes or wake times — and states both directions of the calculation (wake time in → bedtimes out; bedtime in → wake times out). No sibling in the calculator family does this, so an agent can identify it without opening the 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?

"Given a wake-up time... given a bedtime (or 'now')" maps a user intent directly onto the mode choice, which is the main selection decision for this tool. It stops short of naming when not to use it (e.g. arbitrary duration math belongs in calc_hours/calc_date_diff), so it is clear context rather than full routing guidance.

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