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

Goes well beyond the annotations (destructiveHint=true, idempotentHint=true) by disclosing that the previously active version is retired but retained for rollback, that callers need no changes, plus the 404 feature-gate, required publish-scope credential, and the 403 sandbox-workspace restriction. This is exactly the operational context annotations cannot carry.

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?

Four tightly packed sentences, front-loaded with the effect and its consequence for callers before the error and auth prerequisites. Dense but every clause carries distinct information; no wasted words.

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 destructive, idempotent mutation with no output schema, the description covers effect, rollback availability, error conditions, credential scope, and workspace-claim requirement. Nothing an agent needs in order to invoke this correctly is missing.

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 both model_id and version are already documented with their sourcing hints (get_hosted_model, list_hosted_models). The description adds no format or sourcing detail beyond the schema, so the baseline 3 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?

States a specific verb and resource ('Make a version of a hosted model the active one') and explains the effect on callers, clearly distinguishing it from rollback_hosted_model and upload_hosted_model_version. An agent can identify the operation without opening the schema.

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?

Explains when the operation takes effect, that the previous version stays available to roll back to (implicitly routing to rollback_hosted_model), and lists the precondition failures (404 not_released, 403 unclaimed workspace). It doesn't explicitly name the rollback sibling as an alternative, which keeps it short of a 5.

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