Hydration

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 elsewhere. The description adds genuinely new behavioral facts: results are per-day and long ranges are chunked automatically with a 366-day ceiling, which tells the agent it can request wide ranges without manual pagination.

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 short sentences, the payload described first and the chunking caveat second. Nothing is padded, though the fragmentation into a separate sentence for chunking is slightly staccato.

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?

No output schema exists, and the description states the returned unit (per-day intake) and the accompanying goal, plus the range limit that governs the required parameters. That is sufficient for an agent to call it correctly; only the concrete return shape is left unstated.

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% and both parameters are documented with accepted date formats, so the description need not repeat them. It contributes indirectly by clarifying that returned data is per-day and by implying a 366-day span ceiling, but adds no format or default detail beyond the schema.

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 resource and metric: per-day logged water intake plus the goal. An agent can tell this is the hydration getter rather than a generic wellness call. It never names the nearest sibling (garmin_get_nutrition, garmin_get_daily_summaries), so the boundary is left implicit.

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?

Usage is implied rather than stated — you reach for it when you want water intake data. There is no explicit when-to-use, when-not-to-use, or pointer to an alternative such as garmin_get_nutrition if that tool also carries hydration fields.

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