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ratoshniuk

Growatt MCP Server

by ratoshniuk

read_device_parameter

Read-onlyIdempotent

Read a VPP parameter from a Growatt device by specifying device serial number, type, and parameter name to monitor settings like discharge cut-off SOC.

Instructions

Read a VPP (Virtual Power Plant) parameter from a device.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
set_typeYesVPP parameter name, e.g. "set_param_1" or "set_param_23" (discharge cut-off SOC).
device_snYesDevice serial number.
device_typeYesDevice type such as "min", "sph", "spa", "max", "inv", "wit", "tlx". get_devices returns it.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.2.0

TDQS

B3.2/5.0
Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description only restates the read action and provides no additional behavioral context such as auth needs, rate limits, response behavior, or side effects, so it adds no value beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence with no filler. The acronym expansion is useful and every word earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the schema fully documents all three required parameters)Skip the response and the annotations cover safety and idempotency, the description is adequately complete for a simple read operation. The only notable gap is sibling usage guidance, which is already penalized under usage_guidelines.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 100% coverage, including useful examples for set_type and device_type. The description itself does not add parameter-level meaning beyond the schema, so it meets the baseline but does not enhance it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description specifies a concrete action ('Read') and a concrete resource ('VPP parameter from a device'), and expands the VPP acronym. It is clear, but it does not explicitly differentiate itself from sibling tools such as set_device_parameter or get_device_last_data, so it relies on the tool name for sibling distinction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no mention of when to use this tool versus alternatives like set_device_parameter or other read tools. The intended use is only implied by the verb 'Read'; no exclusions or alternative routing are provided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.