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save_tree

Updates only the passive tree in an existing Path of Building build file, applying node allocations or mastery selections back to the original build.

Instructions

Update only the passive tree in an existing build file. Use this to apply tree optimizations or Lua bridge modifications back to the original build.

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": {
      "build_name": "<build_name>",
      "nodes": "<nodes>"
    },
    "name": "save_tree"
  }
}

Input Schema

Name	Required	Description
`nodes`	Yes	Array of node IDs to allocate
`backup`	No	Create backup before modifying (default: true)
`build_name`	Yes	Target build filename to update
`mastery_effects`	No	Mastery selections as object mapping node ID to effect ID (optional)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.1Nov 13, 2026

TDQS

A4/5.0

Behavior3/5

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

With no annotations, the description must carry the behavioral disclosure burden. It discloses that the tool modifies an existing file and only affects the passive tree, which is helpful. However, it does not clarify whether the 'nodes' array replaces the entire tree or merges with existing nodes, nor does it mention backup behavior (though schema notes default true), permissions, or failure handling. This ambiguity prevents a higher score.

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 two sentences, front-loaded with the primary action, and contains no fluff. Every word contributes to understanding the tool's purpose and intended use.

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?

For a moderate-complexity tool with four parameters and no output schema, the description covers the core purpose and usage context sufficiently. It lacks details about return values or post-conditions, but these are not essential for a simple update tool, and the backup behavior is covered in the schema. Adequate overall.

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 provides descriptions for all four parameters (100% coverage), so the description needs to add little extra. The description does not enhance understanding of any specific parameter beyond the schema, though it contextualizes the overall purpose. Baseline 3 is appropriate for high schema coverage.

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 description clearly states the tool's function: 'Update only the passive tree in an existing build file.' This uses a specific verb ('update'), resource ('passive tree'), and scope ('in an existing build file'), distinguishing it from siblings like optimize_tree (which computes optimizations) and snapshot_build (which creates backups).

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

Usage Guidelines4/5

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

The description explicitly instructs when to use the tool: 'Use this to apply tree optimizations or Lua bridge modifications back to the original build.' This provides clear context for the intended use case. However, it does not mention when not to use it or explicitly name alternatives, so it falls short of a 5.

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