blender_set_context

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

Annotations only indicate the operation is not read-only, not idempotent, and not destructive. The description adds valuable behavioral context by emphasizing atomicity and the avoidance of half-applied states, which goes beyond the annotation data. It could mention rollback or error handling explicitly, but the core side-effect story is present.

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?

Two sentences, front-loaded with the action, with no filler. The second sentence earns its place by justifying the atomic design and the tool's reason for existing.

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 5-parameter tool with full schema coverage and no output schema, the description covers the main workflow and failure rationale. It leaves minor gaps, such as the exact treatment of existing selections or the response format, but the atomicity explanation makes the behavior sufficiently predictable for an agent.

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?

All five parameters already have descriptive schema text and enums, so the description does not need to repeat parameter meanings. It does reinforce that mode, active object, selection, and collection are conceptually grouped and should be set together, but this adds only mild semantic value beyond the schema.

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 description opens with a specific action — 'Set mode, active object, active collection and selection atomically' — naming the exact resources it affects plus an atomicity guarantee. It clearly describes a context-preparation tool, but it does not explicitly differentiate it from overlapping siblings like blender_select_objects or blender_edit_mesh.

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 second sentence explains a concrete use case — 'Most operator calls need all four set correctly' — and why this tool should be preferred for that case: one round trip avoids a half-applied state. It does not state when to use an alternative, such as a selection-only tool or blender_edit_mesh, but the intended context is clear.

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