get_hydration

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that results are daily-granular and include both intake and goals, but it omits units/formats and what happens when end_date is null (single day vs. open-ended), leaving behavioral gaps beyond the annotations.

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?

A single front-loaded sentence with no filler. It is efficient, though the brevity comes at the cost of the usage and parameter detail an agent would need.

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 two-parameter read tool with annotations and no output schema, the description covers the core purpose. It still lacks date formatting, end_date default semantics, and any hint about the shape/units of the returned intake and goal values.

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 description must carry parameter meaning and largely doesn't. "Date range" hints that start_date/end_date form a window, but there is no date format, inclusivity, or default-behavior guidance for the optional end_date.

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?

"Get daily hydration intake and goals for a date range" gives a specific verb (get) and resource (hydration intake/goals) plus scope (date range). It is unambiguous, though it does no explicit work to distinguish itself from the many other get_* metric siblings beyond naming hydration as the data domain.

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?

There is no statement of when to use this versus alternatives (e.g., get_daily_summary, which may also surface hydration) and no prerequisites or exclusions. The only guidance is implicit: ask for it when you want hydration data.

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