Verify if a Growatt user name is already registered by providing the login name to prevent duplicate accounts or confirm user presence.
Check whether a Growatt user name exists.
| Name | Required | Description | Default |
|---|---|---|---|
| user_name | Yes | Growatt login name. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds no behavioral detail beyond what annotations provide. With readOnlyHint, idempotentHint, and destructiveHint all present, the description merely confirms an existence check but adds no nuance (e.g., case sensitivity, exact-match behavior, or response shape). The annotations carry the full burden.
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 concise sentence with no redundant words and effectively front-loads the action. It loses one point because it does not use the sentence to convey any usage context or limitations that could have enriched it.
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 tool is simple, has one well-documented parameter, and annotations cover read-only and idempotent behavior. However, the description does not mention what response the agent can expect (e.g., a boolean), which could be easily added to eliminate ambiguity.
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%, so the schema already documents the single parameter with 'Growatt login name.' The description adds no additional semantic detail, but with only one well-documented parameter, the baseline of 3 is appropriate.
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 clear verb ('Check') and a specific resource ('whether a Growatt user name exists'), which distinguishes it from siblings like list_users or register_user. It could be slightly more explicit by naming the alternative (e.g., check_device_sn), but the purpose is unambiguous.
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 description implies this is a lightweight existence pre-check, useful before registration or login, but it does not explicitly state when to use it over list_users or when not to use it. The context is implied rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.