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

Annotations already declare readOnly/idempotent/non-destructive, and the description reinforces 'Read-only.' It also adds genuine behavioral context beyond annotations: the detail_available=false fallback when Google sends no detail, the enumerations of approval_status/review_status, and the evidence payload shape. It does not cover rate limits or pagination, keeping it short of a 5.

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?

Front-loaded with purpose, then return shape, then usage guidance — a logical order. It is dense and long (the enum lists are verbose), but nearly every clause carries information; only minor trimming is possible.

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 an output schema covering return structure, the description supplies everything else an agent needs: the trigger condition, the filtering default, the enum values, and the no-detail edge case. Nothing required to call it correctly is missing.

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%, so the description must compensate. It fully explains only_problems ('true (default) returns just the ads that are not fully approved; false returns every ad with its approval state'), but limit and customer_id get no explanation. Partial compensation for a 3-parameter tool warrants the baseline 3.

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?

Opens with a specific verb+resource and scope: 'Google Ads ad POLICY / DISAPPROVAL report — which ads were DISAPPROVED or limited, and WHY.' It enumerates the exact fields returned (approval_status, review_status, policy topics, evidence), making it unmistakable versus generic siblings like get_report or list_entities.

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?

Gives an explicit trigger condition: 'Use this whenever a campaign or ad group reports HAS_ADS_DISAPPROVED in its status_reasons,' and contrasts what the flag does vs. doesn't tell you. That is a precise when-to-use rule that no sibling states.

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