create_campaign

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

With no annotations provided, the description carries the full behavioral burden. It discloses useful traits beyond the schema: the return contract (campaign_id) and idempotency behavior for retry safety. For a mutating, potentially billing-impacting tool, it does not disclose prerequisites, side effects, or reversal options, but the two disclosed behaviors are genuinely informative and not derivable from structured fields.

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?

Three short sentences, front-loaded with the primary action, then the return-value chain, then idempotency. Some mild redundancy: 'Returns campaign_id for chaining to create_ad_group' and 'Common next: create_ad_group with campaign_id' convey the same idea twice. Otherwise no waste.

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 17-parameter tool with nested targeting objects and no output schema, the description is sparse but compensates through a rich 94%-coverage schema. It supplies the critical orchestration knowledge (what to do with the returned id, retry-safety) that the schema cannot. Not exhaustive about conditional constraints like mode vs product_feed_id/business_agent_id, but the schema carries those.

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 94%, so the schema already documents nearly every parameter; baseline is 3. The description adds marginal value by explaining the idempotency key's purpose (avoid duplicates on retry), which reinforces rather than repeats the schema text. No critical parameter meaning is left unexplained.

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+resource ('Create a campaign') that is unambiguous among siblings like update_campaign, activate_campaign, pause_campaign, and archive_campaign. Adds a workflow hint ('Returns campaign_id for chaining to create_ad_group') that anchors its role. Does not explicitly delimit against create_campaign_hierarchy, but the singular 'a campaign' plus the create_ad_group chain makes the core purpose 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?

Provides implied usage context ('Common next: create_ad_group with campaign_id') that situates this as the entry point of a creation pipeline. However, it never states when to choose this over create_campaign_hierarchy, update_campaign, or the activate/pause tools, and gives no exclusion conditions. The guidance is suggestive rather than directive.

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