add_hydration_dataLog water intake in milliliters to track daily hydration, using optional date and timestamp for precise entries.
Add hydration/water intake data in milliliters.
| Name | Required | Description | Default |
|---|---|---|---|
| date | No | Date in YYYY-MM-DD format (defaults to today) | |
| timestamp | No | Timestamp in ISO format YYYY-MM-DDTHH:MM:SS (optional) | |
| valueInMl | Yes | Amount of water in milliliters (positive to add, negative to subtract) |
Changes observed during successful MCP inspections.
v4.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already include destructiveHint=true, but the description adds no behavioral context about what may be overwritten, whether entry is idempotent, or what happens on negative values. It contributes no information beyond what the schema and title already state.
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, front-loaded sentence with no filler words. It is appropriately concise for the simplicity of the 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?
Although the tool is simple, the description omits behavioral details such as success/error semantics, whether adding on the same date overrides existing data, and the implications of the destructiveHint annotation. The schema covers parameters well, but the description does not fully compensate for the absence of an output schema or broader operational context.
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%, and each parameter already has a clear description in the schema. The description merely restates the unit (milliliters) and the resource name, adding no new meaning 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?
The description uses a specific verb ('Add') and clearly identifies the resource ('hydration/water intake data') plus the unit (milliliters). This distinguishes it from read-only siblings like get_hydration and other add tools like add_weigh_in.
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: the user should call this when adding hydration data. However, there is no explicit statement about when not to use it, no mention of how it differs from get_hydration, and no alternatives are suggested.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.