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

Annotations already declare non-readOnly, idempotent, and destructive. The description adds genuinely new behavior: scene changes (elements/appState) bump version while metadata edits do not, plus pass description=null to clear. These go beyond what annotations convey, though it does not detail what is lost when elements are overwritten despite destructiveHint=true.

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 tight, front-loaded sentences with no filler, each conveying distinct information (updatable fields, version semantics, null clearing, plan gate). Density is high but appropriate.

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 5-param mutation with 0% schema coverage and no output schema, the description covers the important behavioral traits (version bump, null clearing, plan gate) but omits what happens to omitted fields, the return shape, and the meaning of whiteboardId, leaving clear gaps.

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 0%, so the description carries the burden. It adds meaning for name, description (null clears), elements (Excalidraw scene), and appState, but leaves whiteboardId and appState semantics undocumented, so it only partially compensates.

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 (update) and resource (whiteboard) and enumerates the exact updatable aspects: name, description, elements (Excalidraw scene), and appState. The agent can clearly tell this is a mutation tool distinct from create_whiteboard/get_whiteboard, though no sibling is named explicitly.

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 distinction between scene edits and metadata edits usefully signals different use cases, and the plan gate (PRO+) is stated. However there is no explicit when-to-use vs alternative guidance nor any when-not condition; usage is only implied from the field list.

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