vast_update_zone

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

No annotations are present, so the description carries the full burden. It only states 'Update an existing VAST zone' without disclosing whether the update is partial or full replacement, any side effects on associated ad items or campaigns, or whether the zone must exist. This is minimal behavioral disclosure for a mutation tool.

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?

The description is a single, succinct sentence that immediately conveys the tool's purpose. There is no extraneous content, and it is appropriately front-loaded with the action and resource.

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 7-parameter update tool with no annotations or output schema, the description is critically under-specified. It does not mention that only id is required, that other fields are optional for partial updates, or the mutual exclusion between default_vast_ad_item and default_vast_campaign. The schema provides some context, but the description itself fails to convey the update semantics, making it incomplete for reliable tool selection and invocation.

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 baseline is 3. The description adds no parameter information beyond what the schema already documents. The schema itself provides decent descriptions for each field, including the mutual exclusivity of default_vast_ad_item and default_vast_campaign, so the description's lack of param detail is not penalized further.

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 clearly states the action ('Update') and the resource ('an existing VAST zone'), with a specific verb+resource structure. It distinguishes from sibling tools like vast_create_zone, vast_get_zone, and vast_delete_zone by explicitly indicating an update operation on a zone.

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?

No guidance is provided on when to use this tool versus alternatives such as vast_create_zone or vast_delete_zone. There is no mention of prerequisites, scenarios, or exclusions, leaving the agent to infer usage solely from the tool name.

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