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

Annotations declare readOnlyHint=false and destructiveHint=false. The description adds real context beyond that: patch semantics ('omitted fields stay unchanged'), the consent requirement, and the fact that the main Figma frame can be removed. It does not clarify whether frame removal is reversible or what happens to components on the removed branch.

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 compact clauses with the functional scope front-loaded and the governance caveat second, no wasted words. The policy sentence is slightly tangential to the mechanical behavior but is short and justified by the safety framing.

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?

Seven parameters, no output schema, and a mutation surface spanning rename, reparent, component add/remove, and frame removal. The description covers the scope and merge semantics adequately; the only unfilled gap is interaction between addComponentIDs and removeComponentIDs, which the schema also leaves unstated.

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 baseline is 3. The description earns above baseline by stating the merge/patch contract ('omitted fields stay unchanged'), which is semantic information the per-field schema does not convey and which materially changes how an agent builds the call.

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?

Names a specific verb (Updates) and resource (module) and enumerates the exact fields it can touch: name, description, parent, components, and removal of the main Figma frame. This is clearly distinguishable from module_create and product_modules in the sibling list without opening any 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?

Provides an explicit usage gate: only act at the user's request or with their consent, with the rationale that the product structure belongs to the team. It stops short of naming alternative tools or enumerating when-not cases, but the consent condition is a concrete, actionable constraint.

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