create_collection_instance

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

With no annotations, the description carries the full burden and does well: it discloses the shared-data semantics, that edits propagate to every copy, and the non-zero-scale constraint. It omits failure modes (e.g., what happens if collection_name doesn't exist) and whether the operation is reversible without make_instances_real.

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?

Front-loaded with the core behavior and rationale before the Args block; every line earns its place. The Returns section is somewhat redundant given a real output schema exists, adding minor bloat.

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 mutation tool with no annotations, the definition covers behavior, sharing semantics, parameter units, and defaults — enough to invoke correctly. A note on error behavior or its relationship to make_instances_real would close the remaining 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 description coverage is 0%, so the description must compensate, and it does: all five parameters are documented with added meaning beyond the schema — rotation explicitly in radians, name empty-defaults to the collection name, and scale components must not be zero.

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?

States a specific verb and resource ('Place a collection as a lightweight instance') and immediately clarifies the result is 'an empty that shows it', which distinguishes it from create_object/duplicate_object and from make_instances_real.

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?

Explains the 'why' clearly — instances share data so 'a hundred trees cost little more than one' — and notes compatibility with local and linked collections. It does not explicitly name an alternative tool (e.g., duplicate_object or make_instances_real) or a when-not-to-use condition, so routing still requires some inference.

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