Retrieve the value of a model variable by specifying its full path, enabling direct access to model data for inspection.
Get a Model variable value.
| Name | Required | Description | Default |
|---|---|---|---|
| var_path | Yes | Full path, e.g. '/model_name/SIMULATOR' |
Changes observed during successful MCP inspections.
v0.2.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It only indicates a read operation ('Get') and says nothing about return format, error handling, or absence of side effects. This is minimal for a tool with no annotation support.
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 six-word sentence with no filler or redundancy. It is appropriately short and front-loaded for a simple getter, with every word contributing to the stated purpose.
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?
With no output schema and no annotations, the description should clarify what kind of value is returned and how it relates to sibling getters. It does neither, so an agent may call it correctly from the schema but cannot confidently interpret the result or choose it over alternatives.
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 var_path parameter is already documented with an example path. The tool description adds only the 'Model variable' context and does not meaningfully enrich the parameter meaning beyond what the schema provides.
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?
States a specific verb ('Get') and resource ('Model variable value'), so the core action is clear. It does not explicitly distinguish itself from sibling getters like object_get_val or object_get_valof, but 'Model variable' narrows the scope enough to be useful.
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?
No guidance is given about when to use mvar_get versus alternatives such as object_get_val or var_get_table_size. The description provides no context about the intended scenario or exclusions, leaving selection to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.