figma-mcp-go

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

Annotations already declare this is a destructive, non-idempotent write operation (destructiveHint=true, idempotentHint=false). The description confirms it modifies nodes but does not add significant behavioral context beyond the annotations, such as side effects, reversibility, or batch operation semantics.

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 a single, efficient sentence that front-loads the action and target, with the parenthetical providing essential range clarification without verbosity. No extraneous information is present.

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?

Given the low complexity (2 primitive parameters, 100% schema coverage, no output schema) and comprehensive annotations, the description provides adequate context. It appropriately notes the batch capability ('one or more') and value semantics, though it could explicitly acknowledge the destructive modification aspect.

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?

With 100% schema coverage, the baseline is 3. The description adds valuable semantic context beyond the schema by mapping the numeric range to visual outcomes (0=fully transparent, 1=fully opaque), which helps prevent usage errors even though the schema documents the 0-1 range.

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 uses the specific verb 'Set' with the clear resource target 'opacity of one or more nodes'. It effectively distinguishes itself from siblings like set_fills or set_strokes by explicitly focusing on transparency/opacity rather than color or stroke properties.

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 description clarifies the valid input range (0-1) and its semantic meaning, which guides correct invocation. However, it lacks explicit guidance on when to use this versus alternatives like set_fills (which could handle opacity via RGBA values) or prerequisites for the operation.

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