Update variable collection

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

Annotations already flag destructiveHint and idempotentHint, but the description adds real substance beyond them: removing a mode deletes the value every variable holds for it, the last mode is never removed, and 'everything is checked before anything changes' documents a transactional guarantee. It does not restate the idempotency annotation, which is fine.

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 operations, then the destructive warning, then the alternative routing. Dense but nearly every sentence earns its place; the trailing editor note is compact.

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 7-param mutation tool with no output schema and 43% schema coverage, the description covers what changes, what gets destroyed, safety of the operation, and the alternative tool. Only session-selection semantics are left entirely to the schema, a minor 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 43%, so the description must carry weight. It maps the core mutating parameters (name, hiddenFromPublishing, renameModes, removeModes) to concrete operations and warns about delete blast radius, but adds no detail on session or idempotencyKey beyond what the schema already documents. Baseline 3 is appropriate for the coverage gap.

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 resource (variable collection) and enumerates the exact operations: rename, hide from publishing, rename modes, remove modes. It even names the sibling figma_add_variable_mode, so an agent can distinguish it without opening a schema.

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 explicit routing for one action ('To add a mode use figma_add_variable_mode (paid plans)') and states editor availability. It lacks broader when-not guidance (e.g. how it differs from figma_set_variable_properties or figma_delete_variable_collection), but the context is clear.

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