Create a new unconfigured watering zone on an OtO Lawn device. It is immediately waterable, but the throw path must be calibrated in the app.
Create a new unconfigured zone on a device. The device must calibrate the throw path via the app afterwards (cloud-only path mapping is not possible), but the zone appears immediately and is waterable.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| enabled | No | ||
| device_id | Yes | ||
| water_depth_mm | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden, and it does disclose meaningful post-conditions: the zone is unconfigured, appears immediately, is waterable, and requires in-app calibration because cloud-only path mapping is impossible. It still omits permissions, error behavior, and reversibility, so it falls short of a 5.
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?
Two tight sentences, front-loaded with what is created and then the important operational caveat. No filler or repetition.
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 mutation with no annotations and no output schema, the description handles the behavioral side well but leaves the four undocumented parameters entirely to inference, which is a substantial gap for a tool requiring device_id and name.
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?
With 0% schema description coverage across four parameters, the description should compensate but does not: name, enabled, and water_depth_mm are never mentioned, and device_id is only obliquely suggested by 'on a device' without format or source guidance. Only the device relationship is conveyed.
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 gives a specific verb and resource ('Create a new ... zone') plus a distinguishing qualifier ('unconfigured'). It is easy to separate from siblings like rename_zone, delete_zone, list_zones, and get_zone.
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 rather than stated: the creation scenario is clear, but there is no explicit when-to-use/when-not guidance, no mention of the required device_id path, and no alternative tool named for zones that already exist.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.