garmin_api_hydration

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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), so the description earns credit for adding that raw Garmin JSON fields are not normalized — a real trap for downstream parsing — plus the range defaults and cap. The parenthetical about activity search using pagination appears copy-pasted from a different tool and adds mild confusion rather than clarity.

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?

Three short sentences, front-loaded with the resource and the most important behavioral caveat (unnormalized fields). Every clause carries information except the stray pagination parenthetical, which does not belong on a hydration tool.

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?

An output schema exists, so return shape needn't be explained; the description's job is to cover range behavior and data format, and it does both. The only meaningful gap is the unspecified date string format for start_date/end_date.

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 0%, so the two date parameters (start_date, end_date) are documented nowhere in the schema. The description compensates partially by explaining the default window and the 31-day cap, but it never specifies the accepted date format (ISO-8601? epoch?), which is the key unknown for an agent filling these fields.

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 the specific resource (daily hydration statistics) with a clear domain noun, which is enough to separate it from siblings like garmin_api_steps, garmin_api_sleep_summaries, or garmin_api_body_battery. It never names a verb ('get'/'list'), so it reads as a label rather than an action description, but the intent is unambiguous.

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 gives operational context — a 7-day default window and a 31-day maximum — which tells the agent how to scope a request. It does not state when to prefer this over any alternative, nor does it note that no filtering by anything other than date is possible; usage is only implied.

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