join_objects

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

No annotations are provided, so the description carries the behavioral burden and does well: it discloses that geometry is not modified, meshes stay separate inside the datablock, no boolean merge occurs, the first name becomes active, and which names cease to exist afterward. It does not address reversibility/undo or whether non-mesh or hidden objects are handled, which for a mutation tool leaves a small gap.

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 definition is front-loaded with the core purpose, then the TIP routes to the alternative, then args and returns. Some redundancy exists: 'keeps all geometry as-is', 'without modifying geometry', 'meshes remain separate', and 'no boolean merge' repeat the same idea across sentences, which could be tightened.

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?

For a one-parameter merge tool with no annotations, the description covers purpose, alternative routing, parameter meaning, and return shape. An output schema also exists, so the added return explanation is extra assurance rather than a gap.

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 coverage is 0%, so the single parameter 'names' is undocumented in the schema. The description compensates by defining it as a list of object names and adding that the first name becomes the active object, which is meaningful behavior beyond the type.

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?

The first sentence states a specific verb (join) and resource (mesh objects) with scope (keeps all geometry as-is). It explicitly distinguishes itself from booltool_auto_union as the sibling that fuses geometry, so an agent can differentiate without opening schemas.

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?

The TIP explicitly names the alternative, booltool_auto_union, and states the condition that selects it: wanting a true boolean union that merges geometry and removes internal faces. This is exactly the when-to-use-vs-alternative guidance expected.

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