create_component_instance

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

There are no annotations, so the description carries the full burden of disclosing side effects. It only says 'Create an instance' and does not mention whether a new node is returned, what happens if neither componentId nor componentKey is supplied, where the instance is placed when parentId is omitted, or whether the operation modifies the current file permanently.

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 with no filler: the first states the action and resource, the second gives the critical parameter disambiguation. It is front-loaded and every sentence earns its place.

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?

The parameter semantics are well-covered by the schema and the local/library distinction is useful. However, with no annotations and no output schema, the description omits what the tool returns and what happens in edge cases (missing both IDs, both IDs provided, no parentId), so an agent may lack enough context to handle non-happy paths.

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 100%, so the schema already documents each parameter. The description reinforces the componentId vs componentKey distinction, but that information is also present in the schema, so it adds no truly new semantic value.

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 states a specific verb and resource ('Create an instance of a component in Figma') and immediately differentiates the two component sources (local vs published library). This clearly separates it from sibling creation tools like create_frame or create_rectangle.

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?

It gives concrete selection guidance: use componentId with id for local components and componentKey with publishedKey for published library components. It does not explicitly name alternative tools or describe when not to use this tool, but the local-vs-library context is clear enough for an agent to proceed.

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