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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false, so the safety profile is covered structurally. The description adds no behavioral context: it never explains the 'confirm' flag, whether creation incurs billing or starts serving immediately, or whether duplicate names are allowed.

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?

Two short sentences, correctly front-loaded with the action before the advisory tip. Nothing is padded, though the second sentence spends space on campaign strategy rather than call-relevant facts.

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?

For a non-idempotent, open-world mutation with five undocumented parameters and no output schema, the description leaves too much unsaid: the meaning of 'confirm', bid unit conventions, and required IDs are all unaddressed.

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% across 5 parameters, so the schema documents nothing beyond types and requiredness. The description mentions no parameter at all — notably not the ambiguous 'confirm' boolean or 'cpc_bid_major' units — leaving the agent to guess at semantics.

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 pins the parent context ('inside a campaign'), which distinguishes it from siblings like ads_create_campaign and ads_create_ad. It stops short of naming those siblings or clarifying relative ordering, but the resource boundary is clear.

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 second sentence is thematic advice about keyword grouping, not guidance on when to invoke this tool versus alternatives or what prerequisites exist (e.g., campaign must already exist, customer_id must be connected). No when-to-use or when-not-to-use information is given.

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