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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=true, so the safety profile is covered. The description adds useful context: updating replaces the whole draft config, published versions are unaffected, and runs pinned to them keep working. However, it does not disclose what happens if no draft exists yet or what the response contains, so the added value is moderate.

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 sentences with zero waste, and the key scope constraint ('mutable draft') is front-loaded. The parenthetical about calling get_documentation is a useful, purpose-driven digression. The sentence is slightly dense due to the parenthetical, but overall it is efficient and well-structured.

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 rich annotations, 100% schema coverage, and an output schema, the description covers the essential behavioral aspects: what is mutable, what is not, and a critical pre-step for hand-editing configs. The only notable gap is not explaining whether a draft must already exist before calling this tool. Still, an agent has enough to call it correctly.

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%, so the schema already documents all five parameters, including the config shape, environment constraints, and workspace requirements. The description adds a small amount of value by clarifying that config replaces the whole draft and by pointing to get_documentation for the config format, but it mostly restates what the schema already says. 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 precise verb ('Update'), a specific resource ('a splitter's mutable draft'), and the exact scope of the operation: rename and/or replace the draft config. It clearly distinguishes this from publishing by explicitly stating published versions are immutable and unaffected, which differentiates it from the publish_splitter_version sibling.

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 clearly says when to use this tool (to mutate the draft, not the published version) and states that published versions are unaffected. It implies the alternative is publish_splitter_version but does not name it explicitly. The guidance is clear enough for an agent to route correctly, though it could explicitly mention the sibling for completeness.

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