Read or write JVM system properties and environment variables of a running CubeMX engine, and change its log level at runtime.
Read or write the JVM system properties / environment of the running CubeMX engine and change its log level at runtime.
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Property / variable name | |
| value | No | Value for setprop, or level for log | |
| action | Yes | Action | |
| project_id | No | Project id (defaults to the last used) |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does usefully disclose that the target is the *running* engine and that setprop/log mutate live JVM state, but it omits whether changes are persistent or ephemeral, whether they affect other tool calls in the same session, and what happens on an unknown property name.
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?
A single front-loaded sentence that gets straight to the capability with no filler. It is slightly dense in bundling three distinct capabilities (env, properties, log level) into one clause, but no sentence is wasted.
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 4-parameter mutation tool with no annotations and no output schema, the description covers the what but not the consequences: persistence of setprop, global blast radius on the engine, or expected return content for the get* actions. Adequate to attempt a call, not adequate to call it confidently.
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% and the enum is documented, so the schema already carries parameter meaning; the description correctly stays out of the way. It adds only the framing that 'value' doubles as a log level for the log action, which is a modest but real addition beyond the schema text.
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?
Names a specific verb set (read/write/change) and a precise resource (JVM system properties and environment of the running CubeMX engine, plus its log level). No sibling tool covers runtime/process state, so the boundary is implicitly clear, but the description never names it explicitly.
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 states what the tool can do but not when to reach for it versus any alternative, nor any exclusions or prerequisites. With four actions (getenv/getprop/setprop/log) the description gives no cue on which one a given need maps to, leaving that entirely to the enum in the schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.