iaas_update_project_zone_assignments

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

Annotations already declare readOnly=false, idempotent=true, destructive=false and openWorld=true, so the safety profile is covered. The description's one genuine addition is 'asynchronously', which tells the agent the call returns before the change is applied — valuable context not in the annotations. However, it does not say how to follow the async operation (e.g. a request tracker) nor what happens to existing assignments that are omitted from the new list.

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?

It is short and front-loaded, but the first sentence is repeated verbatim with only 'asynchronously' appended, which is wasted space. The raw PUT path is a useful anchor, but the duplication keeps it from being tight.

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?

With annotations covering safety and the schema fully documented, the core is adequate. The remaining gap is operational: for an async, full-replacement mutation on a project's zone assignments, the agent is not told how to confirm completion or that omitting a previously assigned zone effectively removes it.

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%, and the nested body schema documents every field (zoneId, cpuLimit, priority, memoryLimitMB, storageLimitGB, maxNumberInstances) with defaults and caveats. The description adds nothing beyond restating the resource, 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?

The description states a specific verb and resource ('Update all zone assignments to a project') and the underlying PUT path, so the agent knows exactly what is being mutated. The word 'all' signals full-set replacement rather than an incremental patch. It does not explicitly distinguish itself from nearby siblings such as iaas_update_zone or iaas_update_project, so it stops short of a 5.

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?

There is no statement of when to use this versus alternatives, no prerequisites (e.g. project must exist, zones must be registered), and no warning that the call replaces the entire assignment set. The only implicit guidance is the word 'all' and the PUT verb, which the agent must interpret on its own.

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