Create a local water intake draft for review. Check volume and date/time with offset before committing to Fitbit.
Create a local water draft ONLY. Review volume and date/time with offset before saving.
| Name | Required | Description | Default |
|---|---|---|---|
| at | Yes | ||
| requestId | Yes | ||
| milliliters | Yes |
Changes observed during successful MCP inspections.
v0.1.0-alpha.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=false. The description adds important context beyond annotations: the result is a 'local draft ONLY' and should be reviewed before saving, clarifying that this is a temporary write-like step rather than immediate persistence. It does not discuss auth or rate limits, but those are not implied by the tool's scope.
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 two short, front-loaded sentences with no waste. The key constraint ('local draft ONLY') and the intended review step are both stated compactly.
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?
The description covers the draft-creation purpose and review step, and annotations cover safety and idempotency. But for a three-parameter workflow tool, it omits the role of requestId and does not explicitly connect the draft to sibling commit/cancel operations, leaving the agent to infer the two-phase workflow.
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 compensate. It mentions 'volume' (mapping to milliliters) and 'date/time with offset' (mapping to at), partly clarifying two of three required parameters. However, it says nothing about requestId, which is required and likely used for idempotency/deduplication, leaving a significant gap.
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 states a specific verb ('Create') and resource ('local water draft') with scope ('ONLY'), and the phrase 'before saving' distinguishes it from a commit/persist sibling. An agent can immediately tell this is a preview/draft-creation tool rather than a save or read tool.
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?
It gives clear context: use this to create a local draft, then review volume and date/time with offset before saving. That implies the tool is for pre-commit review and should be followed by a save operation, but it does not explicitly name the alternative tool (e.g., fitbit_commit) or state when not to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.