List Cluster Regions

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

Annotations already declare readOnlyHint, so the safety profile is covered. The description adds genuinely non-obvious behavior: results are limited to public and BYOC regions visible to the org, and only regions with a ready deployment are returned. It omits whether disabled regions appear at all and what fields come back.

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, front-loaded with the action and scope. The middle sentence on downstream use is the most valuable part and sits early; nothing is redundant, though the phrasing 'its prerequisite size and S3 checks' is slightly compressed.

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 simple read tool with annotations covering safety, the main gaps are result shape (no output schema, and the description never says a region ID/enabled flag is returned) and the undocumented organization parameter. It conveys the filtering semantics well but leaves the agent guessing at the return payload.

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 0% for the single required 'organization' parameter, so the description carries the burden of clarifying it. It says 'accessible to an organization', which hints the parameter scopes results to that org, but it never explains accepted format (ID vs name) or whether omission is possible.

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 ('List the public and BYOC regions') and scopes the result to an organization, which is distinguishable from sibling list-cluster-sizes and list-clusters. It stops short of explicitly contrasting with those siblings, but the scope is clear enough to select the tool.

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 implies downstream usage ('Use an enabled region ID for cluster creation and its prerequisite size and S3 checks') and gives a precondition ('Regions need a ready deployment'). That is useful implicit context, but it never states when to call this versus alternatives or what to do if the list is empty.

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