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

Annotations already declare this is a non-readonly, non-idempotent, non-destructive mutation, so the description adds value by specifying that both target and source batches are restored to pre-merge states. It also notes confirm-based commit vs. dry-run and idempotency validation, though those are also visible in the schema. It does not clarify irreversibility or error behavior when no active merge 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?

Two tight sentences with the core action and restoration effect front-loaded. Every clause carries information and nothing is redundant or buried.

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 mutation tool with no output schema, the description correctly covers the high-level effect and the confirm/idempotency mechanics. It does not address edge cases such as what happens if the merge is not active or whether a successful unmerge returns the restored batch records, but annotations offset some of that burden.

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 100%, so all four parameters are already documented in the input schema. The description mentions confirm and idempotency validation but adds no syntax, defaults, or constraints beyond what the schema provides. Baseline 3 is appropriate.

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 states a specific verb and resource — 'Undo an active batch merge' — and names the exact effect on both the target and source batches. It is immediately distinguishable from the sibling merge_bird_batches as its inverse operation.

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 word 'active' implies this applies only to currently merged batches, giving some usage context. However, there is no explicit when-to-use guidance, no prerequisites (e.g., required permissions), and no named alternatives or when-not conditions.

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