Set layout grids

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

Annotations already declare readOnly=false, destructive=false, idempotent=true, and the description adds real behavioral content on top: grids render only in the editor and never in exports, an empty array deletes grids, per-item results mean one node failing does not fail the call, and FigJam/Slides support is unverified. These are exactly the traits an agent cannot infer from the schema.

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?

Three dense sentences, front-loaded with the purpose before behavioral notes, return shape, and editor availability. No filler or restatement of the tool title; every clause carries new information.

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?

With no output schema, the description supplies the return shape (`{ updated, items: [{ id, ok, error? }] }`) and the partial-failure semantics, which is the main thing an agent would otherwise have to discover blindly. Combined with the removal behavior and editor support notes, nothing needed to invoke this correctly is missing.

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 75%, so the schema already carries most parameter documentation (session, idempotencyKey, nodeIds, and the nested properties). The description still adds semantic value by giving a concrete grid example ("12 columns, 24 gutter, 80 margin") and by defining the empty-array removal case, which the schema does not express.

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?

States a specific verb and resource ("Replace the layout grids of frames") and then defines the resource concretely with the three supported patterns (columns, rows, square grid) and a worked example. This is enough to separate it from siblings like figma_create_grid_style and figma_set_slide_grid 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 one concrete usage rule ("An empty `grids` removes them") and states editor availability, which is genuinely useful context. However, it never says when to prefer this over figma_create_grid_style or figma_set_slide_grid, nor any prerequisite such as the target nodes needing to be frames. Usage is implied rather than directed.

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