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

With no annotations provided, the description carries the full behavioral burden. It discloses that the pivot is normalized to the bbox, that resizing keeps the pivot anchored, that the operation is static rather than animated, and that it applies only to specific leaf types. It also clarifies the relationship between the pivot and rotation/scale behavior, which goes well beyond a bare 'sets pivot' statement.

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 focused sentences with no filler. The purpose is front-loaded, the key behavioral constraints follow, and the group alternative is given in the last sentence. Every sentence adds distinct value.

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 simple three-parameter setter with a fully self-documenting schema and no output schema, the description covers the operation scope, behavioral semantics, and the key alternative. Nothing critical is missing for an agent to decide whether and how to invoke this tool.

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%, and every parameter has a meaningful description: anchor explains the 9 enum values, elementId specifies allowed prefixes, and projectId explains its source and mutation role. The description adds contextual behavior but no new parameter-level detail, so the baseline of 3 is appropriate.

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 opens with a specific verb and resource: 'Set the rotation / scale pivot anchor for an image, video, shape, or text leaf.' It clearly defines the 9-anchor behavior and distinguishes itself from group-related operations by pointing to move_layer for groups. This makes the tool immediately distinguishable from its many set_* siblings.

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 explicitly states the target element types (leaf-level images, videos, shapes, text), notes that the pivot is static/not animated, and provides an explicit alternative: 'For groups, use move_layer with x/y to set the group's absolute pivotX/pivotY instead.' This gives clear when-to-use and when-not-to-use guidance.

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