direct_set_region_excludes

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

With no annotations, the description carries the burden of disclosing behavior. It explicitly says this is a WRITE operation, explains that positive IDs are converted to stored negatives, states it preserves existing positives, and notes the allow_write=true requirement. Missing details like how existing negatives are handled and exact scoping are gaps, but the core behavior is well conveyed.

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 compact and front-loaded with the 'WRITE:' flag and purpose. It delivers essential information in two sentences with no filler, making it easily scannable for an agent.

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?

Given the lack of annotations and output schema, and 5 parameters, the description covers the core behavior but leaves ambiguity about how campaign_ids scopes the operation, what project keys are valid, and the exact dry-run semantics. It is sufficient for a basic understanding but incomplete for nuanced use.

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 critical meaning to the primary parameter region_ids by explaining the positive-to-negative conversion, beyond the schema's simple 'Positive GeoRegionId of subjects to EXCLUDE'. It also references allow_write. However, dry_run, project, and campaign_ids are not explained in either description or schema (60% coverage), so it doesn't fully compensate for all parameters.

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 tool's function: 'WRITE: add negative RegionIds on all ad groups of campaigns'. It includes a concrete example ('exclude subjects under Russia 225') and distinguishes itself from sibling tools by specifying 'all ad groups' and the negative-region focus.

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 a clear use case ('exclude subjects under Russia 225') and implies the tool is for adding negative regions across campaigns. It doesn't explicitly mention alternatives or when not to use it, but the context and sibling names suggest its specific role without needing exclusions.

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