Each tool has a clearly distinct purpose: auditing an existing STL, generating and auditing a reference box, and listing presets. The generate_reference_box tool's inclusion of an audit step does not blur its boundary because it is explicitly a fixture-creation operation.

All three names follow a consistent snake_case verb_noun pattern: audit_stl, generate_reference_box, list_presets. The convention is predictable and readable.

Three tools is on the low end but fits the focused purpose of an STL audit critic. Each tool earns its place, though the surface is somewhat thin for anything beyond basic auditing.

The core audit operation is covered, but the surface has notable dead ends: presets can be listed but not run or inspected, and there is no repair or re-audit workflow for failed meshes. Agents can work around this for simple audits but will hit gaps in a full CAD validation lifecycle.