Create ad group

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

Annotations already declare a non-read-only, non-destructive, open-world write. The description adds genuinely new behavioral facts beyond that: the default PAUSED status, the micro-currency convention (1 USD = 1000000), and the CBO constraint that several fields must match the campaign with goal_value null. It does not mention permissions or response behavior, but the added context is substantive.

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?

Four front-loaded sentences, each carrying a distinct constraint (hierarchy, currency, default state, CBO rule) with no filler. Slightly dense but every sentence earns its place.

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 a deep nested schema, no output schema, and full schema coverage, the description supplies the defaults and cross-field constraints the schema cannot express. It is nearly complete for correct invocation; only permission/auth context is absent, which is minor here.

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 100%, so a baseline of 3 would apply. The description goes further, clarifying the micro-currency unit for monetary fields and the CBO rule that bid_strategy, bid_type, goal_type, optimization_goal and view_through_conversion_type must match the campaign and goal_value must be null — semantics not present in the schema.

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?

States a specific verb and resource ('Create an ad group') and situates it in the object hierarchy ('inside a campaign'), which orients the agent relative to reddit_ads_create_campaign and reddit_ads_create_ad. It does not explicitly name those siblings, so it falls just short of full sibling differentiation.

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 clear operational guidance ('Create it PAUSED unless the user asks otherwise') and a conditional prerequisite for campaign budget optimization. It does not cover when to prefer this tool over alternatives or ordering requirements relative to campaign creation, but the context is well supplied.

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