transaction.begin

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

Annotations already declare destructiveHint=true and idempotentHint=true. The description adds that the transaction is 'single', 'reversible', and 'preview'-oriented, which gives useful context beyond the annotations. However, it does not explain what happens if a transaction is already active or how idempotency is enforced; no contradiction with annotations exists.

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 a single, front-loaded sentence with no filler words. Every term contributes to the core action and scope, making it easy to parse quickly.

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?

Despite having annotations and an output schema, the description omits critical operational context: the meaning of expected_scene_generation, the role of idempotency_key, and how this transaction relates to commit/rollback. For a mutating tool with required parameters and a destructive hint, this is a significant completeness gap.

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 0%, and the description says nothing about the four parameters: label, viewport_id, idempotency_key, and expected_scene_generation. An agent cannot infer the meaning of expected_scene_generation or how to generate a correct idempotency key from the description alone, so the description fails to compensate for missing schema docs.

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 uses a specific verb ('Begin') with a clear resource ('reversible preview transaction') and scope ('for this Blender instance'). It distinguishes itself from transaction.commit and transaction.rollback by naming the action as beginning, though it does not explicitly reference those 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?

There is no guidance on when to begin the transaction versus when to use commit/rollback, nor any mention of prerequisites such as matching expected_scene_generation or ensuring no existing transaction. The only usage signal is the verb 'Begin', which is insufficient for an agent to sequence actions correctly.

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