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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds value beyond them: all edits commit atomically, version-conflict handling via the latest successful read/write version, and a compact committed receipt return. It does not restate irreversibility but that is already in annotations.

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?

Front-loaded with the core action, then four tight sentences each carrying distinct operational info (version source, selection URL, subtree read, receipt). Dense and jargon-heavy but no wasted sentences; slightly hard to scan.

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 complex five-variant atomic batch tool with an output schema present, the description covers the workflow, versioning, and return-receipt expectations adequately. It omits failure/conflict error behavior and partial-failure semantics, which an agent handling retries might want.

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 100% (baseline 3), but the description adds meaning beyond the schema: baseVersion is the exact version to target including one from a prior write, and the canvas 'selection URL' constrains the whole batch. These clarify param intent rather than merely echoing field names.

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 ('Apply ... edits together in one atomic mutation') and enumerates the five edit kinds (text, styles, rename, duplicate, move), so it is distinguishable from canvas_render and canvas_write_html at a glance. The 'atomic mutation' framing is precise and avoids tautology.

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?

Gives strong procedural guidance: use ids from the input version, no intermediate read needed just to advance a version, and read only the missing subtree when ids are unknown. It does not, however, name an alternative sibling (e.g. canvas_write_html) or a condition selecting one over the other, so it stops short of explicit when-not routing.

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