direct_add_adgroups

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

With no annotations, the description carries the burden of disclosing side effects. It explicitly states 'WRITE', indicating a mutation, and requires 'allow_write=true' to perform the mutation, which is an important behavioral safeguard. It also discloses the default region_ids behavior. However, it does not describe the outcome of the write or whether it is reversible, though the add semantics are clear.

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 extremely concise, a single sentence of specification. It front-loads 'WRITE' and packs the essential structure, 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 tool with moderate complexity, the description covers the key non-obvious aspects: the group object format, the default region, and the write gating. It doesn't explain campaign_id beyond schema, but that is a required parameter. The lack of output schema means return values are not needed. Overall, it is sufficient for correct 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?

The description adds crucial semantics for the 'groups' parameter by specifying the object structure (name required, region_ids optional) and the default value of [225] for region_ids. This goes beyond the bare schema, which only lists types. It also reiterates the allow_write/project requirements, though those are already in parameter descriptions. With 40% schema coverage, the description partially compensates but does not cover campaign_id or dry_run.

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 identifies a write operation for adding ad groups, specifying the input format as groups=[{name, region_ids?}]. The verb 'add' and resource 'adgroups' are explicit, distinguishing it from sibling tools that list, update, or delete adgroups.

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?

The description provides no explicit guidance on when to use this tool over alternatives like direct_update_adgroup_regions or direct_set_negatives, but the 'WRITE' marker and the groups parameter imply it is for adding ad groups. It does mention the condition 'allow_write=true + project scope' which gives context for invocation, but no when-not or alternative comparisons are provided.

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