Draft a Reddit campaign

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

The description adds meaningful behavioral detail beyond the sparse annotations: the campaign is created PAUSED, a preview is returned, budgets are validated against max_daily_budget, times must be ISO 8601, and schedule hours apply in viewer-local time. This is exactly the kind of context an agent needs and the annotations alone do not provide.

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 dense and uses clear labels (objective, funding_instrument_id, schedule) to structure information. The schedule explanation is long but necessary given the two accepted formats and edge cases. It is not padded, though a more formatted layout could improve scannability.

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 tool's complexity (16 params, no enums) and the presence of an output schema, the description covers the essential workflow: prerequisites, budget ownership, schedule semantics, and next steps. It is not exhaustive for optional bidding parameters, but it is sufficient for an agent to make a reasonable first call on a draft-preview tool.

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 0%, so the description must compensate. It does explain objective values, funding_instrument_id sourcing, CBO-dependent required fields, and the schedule block formats. However, several parameters like bid_strategy, bid_type, optimization_goal, spend_cap, and start_time/end_time are not described, leaving the agent to guess their valid values.

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 opens with a specific verb and resource: 'Draft a new Reddit campaign (created PAUSED) — returns a PREVIEW.' This clearly states what the tool does and its immediate output. It also distinguishes itself from related siblings by explicitly naming the follow-up draft_reddit_ad_group and by focusing on Reddit-specific semantics.

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 gives practical usage context: where funding_instrument_id comes from, how to switch budget ownership via campaign_budget_optimization, and what fields become required in that mode. It explains the schedule format and advises following up with draft_reddit_ad_group. It does not explicitly contrast this with draft_campaign or other alternatives, so it loses one point.

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