Authenticate with the Powerwall gateway using your password (last 5 digits of serial) and optional email to obtain an access token for system monitoring and control.
Authenticate with the Powerwall gateway and obtain an access token
| Name | Required | Description | Default |
|---|---|---|---|
| No | Email address (optional) | ||
| password | Yes | Password (last 5 digits of Gateway serial number or custom password) | |
| username | No | Username (typically 'customer') | customer |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full burden. It states the core action and result, but does not disclose side effects (e.g., token storage for subsequent calls), failure conditions (invalid credentials), or that it is a prerequisite for other tools. This is a minimal disclosure typical of a login operation but lacks depth beyond the obvious.
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, efficient sentence that front-loads the action and outcome. There is no redundant wording, and it is appropriately concise for a straightforward login 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?
For a simple login tool with fully documented parameters and no output schema, the description covers the essential purpose. However, it omits integration context (e.g., that this token is needed for subsequent API calls) and does not explicitly mention usage prerequisites, leaving minor gaps in completeness.
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?
The input schema has 100% coverage, with each parameter (email, password, username) having descriptive text. The description adds no parameter-level information beyond what the schema provides, so the baseline of 3 applies.
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 clearly states the specific action: 'Authenticate with the Powerwall gateway' and the outcome 'obtain an access token'. It distinguishes itself from the sibling tools (e.g., getters, logout) by being the only authentication entry point, so an agent can easily identify its role.
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 its usage as the initial authentication step for accessing Powerwall data, but it does not explicitly state when to use it (e.g., 'call this before other powerwall tools') or when not to use it. No prerequisites or alternatives are mentioned, leaving the context implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.