transaction.begin

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

All annotations are false, so the description carries the full burden of disclosing behavior. It merely calls the operation a 'lifecycle operation' without explaining side effects, state changes, required session state, or failure modes. The agent is left completely in the dark about what happens at runtime.

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 extremely short, but this is under-specification rather than effective conciseness. The single sentence does not add meaningful information; it fails to earn its place because it only restates the tool's identity without explaining its purpose or behavior.

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?

Even though an output schema exists unusual for yield, the description is inadequate for a tool with mutation-like semantics (all annotations false). The agent cannot understand what a transaction is in this harness, how to initiate one correctly, or how it fits into the broader workflow with commit and rollback siblings. This definition is critically incomplete.

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% and both parameters have inline descriptions ('Stable request id for replay safety' and 'Harness milestone transaction id'). The tool description adds no additional semantic information beyond what the schema already provides, so the baseline score of 3 for full schema coverage applies.

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 'Guarded Harness lifecycle operation `transaction.begin`' is nearly a tautology of the tool name and title. It labels the operation as a lifecycle operation but does not state that it begins or starts a transaction, leaving the agent to infer the verb from the title. It does not clearly distinguish what this tool does versus a generic lifecycle management function.

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 provides zero guidance on when to use this tool, what prerequisites exist, or how it relates to sibling tools like blender_transaction_commit and blender_transaction_rollback. No context is given for when a transaction should be started or what 'guarded' implies, leaving the agent without any decision-making information.

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