blender.begin_transaction

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

With no annotations, the description carries the full burden and does well: it discloses the recording semantics of the transaction, that rollback reverts all recorded calls, and the specific failure mode TRANSACTION_ACTIVE when one is already open. Missing details such as permission requirements or nesting behavior keep it from a 5.

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 the parameter note, then the error condition, each in its own compact block. Every sentence earns its place; no filler or repetition.

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?

An output schema exists, so return values need not be described. For a single-optional-parameter transaction opener, the definition covers semantics, parameter meaning, and the key failure mode, leaving nothing an agent needs before calling it.

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 must compensate, and it does: the label parameter is explained as an optional name marking the starting point, with a concrete example ("layout") and its use case (later rollbacks by name). This adds real meaning beyond the bare string type in the schema.

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 ("Open a transaction") and explicitly names the sibling that undoes it (blender.rollback_transaction), so the agent can separate it from the rollback path. It does not contrast with the other transaction siblings (commit_transaction, checkpoint), so the differentiation is partial rather than complete.

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?

"Every mutating call until commit or rollback is recorded" communicates the intended position in the workflow (open before mutating, close via commit/rollback), and the named rollback_transaction alternative gives context. There is no explicit when-not or comparison to checkpoint, so it falls short of full routing guidance.

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