update_rollout

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

With no annotations, the description carries the transparency burden. It discloses two key behavioral traits: passing 1 completes the rollout and changes status to 'completed', and updating a halted release resumes it. These go beyond the raw schema. However, it does not mention what happens on validation failure, rate limits, or whether package_name can be omitted, leaving some gaps.

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?

Three short sentences, each earning its place: the core action, the special value behavior, and a prerequisite tip. No filler or redundancy. The verb and resource are front-loaded in the first sentence.

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 5 params and no output schema, the description covers the essential state transitions and the prerequisite to read current fraction. It lacks details on the response or what happens if the track is not in an updatable state, but the schema fills parameter gaps. Overall, it is reasonably complete for the tool's moderate complexity.

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 the schema already explains every parameter. The description adds no new parameter-level semantics beyond repeating that user_fraction=1 completes the rollout, which the schema also states. It does not clarify validate_only or changes_not_sent_for_review further, but the schema descriptions are sufficient.

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 opens with 'Change the staged rollout percentage of the in-progress release on a track' – a specific verb ('Change') and resource (staged rollout percentage on a track) that clearly differentiates from siblings like halt_rollout or promote_release. It also explains the completion and resume behavior, reinforcing its unique role.

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?

It gives explicit actionable guidance: 'Use get_track to see the current userFraction first.' This tells the agent the prerequisite step. It also implies usage on in-progress releases and clarifies special cases (complete rollout, resume halted release), but it does not explicitly state when not to use it or compare with alternatives like halt_rollout or promote_release.

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