Add a text layer

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

Given annotations (readOnlyHint=false, destructiveHint=true), the description adds useful behavioral context beyond them: it discloses the font loading sequence, refusal of unavailable fonts rather than substitution, and the width-to-wrapping behavior. These are meaningful traits that inform the agent about expected side effects and failure modes. It does not contradict the annotations; it complements them with specifics.

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 filler. The primary action is front-loaded, and every sentence adds information: the creation action, font handling, and width behavior. It is concise and structured effectively for quick comprehension.

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 somewhat complex tool with 10 parameters and no output schema, the description covers the key behaviors: creation, font loading and substitution refusal, and width semantics. It omits details like parent handling, color, or position, but these are reasonably inferred from the schema. Given the annotations already cover the destructive nature, the description is sufficiently complete for an agent to call the tool correctly in most cases.

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 70%, so some parameters lack descriptions. The description adds context for the width parameter (wrap vs. hugging text) which is already in the schema's width description, and it mentions font behavior that relates to fontFamily but is more behavioral than parameter-specific. It does not clarify the undocumented parameters (e.g., fontSize) or add syntax details. The added value is modest, so a baseline of 3 is appropriate given the 70% 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 tool creates a TEXT layer with given words, using specific verb 'Creates' and resource 'TEXT layer'. It differentiates from sibling creation tools (rectangle, ellipse, svg) by specifying text, and from editing tools like set_text by the creation action. The text is explicit that it adds a new text layer.

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 does not explicitly state when to use this tool versus alternatives like figma_set_text or figma_set_text_style. It implies creation of a new text layer, but offers no guidance on when not to use it or conditions that select this tool over siblings. The behavioral notes about font availability are more akin to constraints than usage guidance, so the tool falls short on this dimension.

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