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mpfb_get_macro_details

Read-onlyIdempotent

Reads a MakeHuman character's current macro sliders—gender, age, muscle, race weights and more—without changing anything, so you can plan relative phenotype edits.

Instructions

Read a MakeHuman character's macro details - its phenotype sliders: gender, age, muscle, weight, proportions, height, cupsize, firmness and the three race weights. Changes nothing.

Call this before mpfb_set_macro_details: that tool leaves unnamed sliders alone, so knowing the current values is what makes a relative change ("a bit older") possible. An unresolvable name, nothing active, or an object with no basemesh among its relatives each come back as found: false with a message, not as an error.

result carries:

macro_details: the current values in MPFB's own nested shape (gender, age, ..., plus race holding asian, caucasian and african). mpfb_set_macro_details returns the same shape but takes its arguments flat: race.asian is set as race_asian.
default_macro_details: what MPFB considers neutral - every slider 0.5, every race weight 0.33.
race_sum and race_normalized: the three race weights are independent 0.0-1.0 properties and MPFB does not normalize them. The default sums to 0.99; setting race_asian to 1.0 and leaving the others alone builds a character from weights summing to 1.66, which is legal and probably not what was wanted.
macro_target_stack and macro_target_count: what those values mean in target terms, each entry carrying the target_fragment MPFB loads from disk and the shapekey_name it becomes. Neither is a name any tool accepts as input; they explain the shape, they do not address it.
current_macro_shapekeys: the macro shape keys actually on the mesh now, under the names they are stored with - the same vocabulary as macro_target_stack's shapekey_name, so the two can be compared directly. If they disagree, the properties were changed without a recalculation and mpfb_set_macro_details will repair it. macro_drift is that comparison made for you, weights included. current_macro_shapekeys_decoded is the same list in MPFB's readable form, for reading rather than comparing.
has_shapekeys and is_human_project: a mesh tagged as a basemesh but never built by MPFB reads back a full set of macro properties that mean nothing. These two are how that is told apart.
basemesh_name, subject_name and subject_resolved_by ("name" or "active").

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 3, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds substantial context beyond them: 'Changes nothing', the non-error failure contract ('found: false' with a 'message' for unresolvable names, no active object, or no basemesh), and the drift-detection semantics linking this tool to the setter's repair behavior.

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

Conciseness4/5

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

Front-loaded with purpose and the key call-ordering rule, then organized into scannable bulleted result fields. It is long and much of the return-field inventory is duplicated by the existing output schema, but the non-obvious semantics (unnormalized race weights, drift, target-vs-input vocabularies) genuinely earn the space.

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

Completeness5/5

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

Given an output schema, a single name parameter, and a subtle setter relationship, the description covers purpose, ordering, failure modes, field interpretation, and the traps (race weights summing above 1.0, stale shapekeys, mesh tagged as basemesh but never built). Nothing an agent needs to call it correctly is missing.

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

Parameters4/5

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

One parameter at 0% schema coverage, but the description compensates by explaining name resolution and the 'subject_resolved_by' ('name' or 'active') fallback, plus that an unresolvable name yields 'found: false' rather than an error. It covers the resolution contract well, though it never states the default-when-omitted behavior explicitly for the agent.

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?

States a specific verb and resource ('Read a MakeHuman character's macro details - its phenotype sliders') and immediately enumerates the exact sliders returned. An agent can distinguish it from mpfb_get_character_summary or mpfb_get_target_stack without opening any schema.

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

Usage Guidelines5/5

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

Explicitly says 'Call this before `mpfb_set_macro_details`' and explains why: the setter leaves unnamed sliders alone, so current values are needed to make a relative change like 'a bit older'. This is a concrete when-to-use plus a named alternative, not implied guidance.

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