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

Beyond the annotations (readOnly, idempotent, non-destructive), the description adds valuable behavioral detail by enumerating the specific checks performed: no cookies, no fingerprinting, contextual targeting, data residency, revenue transparency, consent basis, and agent transparency. It also describes the output format, giving a fuller behavioral picture.

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 well-organized into distinct sections (tool_description, when_to_use, combination_hints, output_format), each concise and purposeful. No filler or redundant content, and the key information is front-loaded.

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 only one parameter, clear annotations, a defined output format, and explicit workflow hints, the description fully covers what an agent needs to select and invoke this tool correctly. The combination hints also situate it within the broader campaign lifecycle.

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 sole parameter media_buy_id is already fully described in the schema with 'Media buy UUID to check' and 100% schema coverage. The description does not add further parameter-level detail beyond referencing 'a media buy' context, so the schema carries the semantic burden.

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 'Check nDSG/GDPR/EU AI Act compliance status for a media buy' with a specific verb and resource, and it uniquely distinguishes this tool from sibling tools like get_campaign_report or get_inventory_item. The compliance scope is explicit and actionable.

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 'when_to_use' section explicitly states 'Before activating a campaign or for compliance audits,' and the combination hint 'create_media_buy → get_compliance_status → activate' provides concrete workflow guidance. This clearly communicates when to use this tool versus alternatives.

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