get_daily_hydration

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

No annotations are provided, so the description must cover behavioral implications. It does disclose that the response includes the daily goal, which is somewhat useful, but it does not explain units, timezone handling, the meaning of null day, or whether this is a safe read-only call. This leaves meaningful uncertainty for an agent.

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?

The description is a single compact sentence with no filler. It front-loads the core concept ('fluid intake') and adds only the essential scoping detail about date format.

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 simple one-parameter getter, the description conveys the main return content and the expected argument format. Yet with no output schema and no annotations, it leaves gaps around default behavior, units, and exact response structure, making it adequate but not fully complete.

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 0%, so the description must compensate. It adds the expected format (YYYY-MM-DD) and ties the parameter to a single day, which is helpful. However, it does not explain the behavior when day is null or omitted, even though the schema marks the parameter as optional with a null default.

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 identifies the resource as daily fluid intake and specifies that it includes the daily goal, scoped to a single day with YYYY-MM-DD format. This distinguishes it from the sibling get_hydration_history, though the description does not explicitly name or contrast that alternative.

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 phrase 'for a day (YYYY-MM-DD)' implies this tool is for retrieving a single day's hydration data rather than a history or range. However, it provides no explicit guidance about when to prefer this over get_hydration_history or what happens when the optional day parameter is omitted.

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