ltspice-mcp

load_library

Load SPICE library files or directories into the simulation session to make their models available for circuit design and analysis.

Instructions

Load a SPICE library file (.lib, .mod) or directory of library files into the session.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "path": "<path>"
    },
    "name": "load_library"
  }
}

Input Schema

Name	Required	Description	Default
`path`	Yes	Path to library file or directory

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 21, 2026

TDQS

A3.5/5.0

Behavior2/5

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

Annotations are all false, so the description carries full weight. It only says 'load into the session' but does not disclose whether loading replaces existing libraries, is idempotent, has side effects, or what happens on errors. This is minimal disclosure for a state-modifying operation.

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 sentence, directly front-loaded, with no redundant words. Every element adds meaning, making it highly concise and well-structured.

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

Completeness3/5

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

The tool is simple (one parameter, no output schema), and the description covers the core action but omits behavior like replacement policy, existence checks, or interaction with other tools (e.g., whether loaded libraries are automatically used by simulations). Given the minimal annotations, it is adequate but not fully comprehensive.

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?

Schema coverage is 100% with a single parameter described as 'Path to library file or directory'. The tool description adds file extensions (.lib, .mod) and clarifies that a directory is accepted, providing marginal value beyond the schema. Baseline 3 is appropriate.

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

Purpose5/5

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

The verb 'Load' clearly specifies the action (loading a SPICE library file or directory), and it explicitly names the resource types (.lib, .mod). It distinguishes from siblings like unload_library and list_libraries by stating the purpose of making libraries available to the session.

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

Usage Guidelines3/5

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

The description implies usage context ('into the session') but does not explicitly state when to use this tool versus alternatives like find_model or unload_library, nor does it mention any exclusions or prerequisites. Usage 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.