combine_as_variants

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

Annotations already indicate readOnlyHint=false, so the description adds value by disclosing the side effect: 'The components are reparented into the new set under parentId.' It also states the return shape, which helps set expectations. Minor gaps exist (e.g., no mention of permission/undo), but it goes beyond annotations.

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 description is three sentences with no fluff: the core action, a necessary prerequisite, and side-effect/return info. It is front-loaded and every sentence adds value.

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 description covers the action, prerequisite, side-effect, and return value. There's no output schema, so including the return format is beneficial. Minor edge-case behaviors (error conditions for non-COMPONENT nodes) are left to the schema, but overall it's sufficiently complete for a 3-parameter mutation tool.

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 100%, with each parameter described in the input schema. The description adds little beyond the schema, aside from restating the default parent behavior already present in the schema. Baseline 3 is appropriate given full schema coverage.

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 clearly states the action: 'Combine two or more existing COMPONENT nodes into a single COMPONENT_SET (a variant set).' It uses a specific verb and resource, and differentiates from sibling tools like group_nodes or reparent_nodes by explicitly targeting variant-set creation.

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 provides clear context and a prerequisite: 'Name each component with Figma variant syntax... beforehand so the set derives its properties.' No alternatives or exclusions are mentioned, but the usage intent is well-understood.

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