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

Annotations already declare readOnlyHint=false and destructiveHint=false, and the description adds meaningful context: the plan is immutable, must be separately confirmed, and does not change advertising entities. This clarifies the write-to-plan versus write-to-account distinction, which is not captured by annotations alone.

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 compact sentences with no filler. The key constraints—immutable plan, separately confirmable, no entity changes—are front-loaded before the lower-level detail.

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 an output schema exists and annotations cover the safety profile, the description supplies the essential behavioral context: it creates a plan rather than changing entities and requires separate confirmation. A slightly clearer pointer to the confirm/apply workflow would make it fully complete for an agent navigating this sibling set.

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 the nested schema already documents storeId, skus/asins precedence, adGroupId, adGroups, and campaignId in detail. The top-level description adds little parameter-specific meaning beyond saying the tool creates SP or SD product ads, so the schema remains the primary source of parameter 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?

The description states a specific verb and resource: it prepares an immutable Amazon Ads plan and creates Sponsored Products or Sponsored Display product ads. It also distinguishes itself from mutation siblings by noting it persists an internal plan 'without changing advertising entities,' though it stops short of naming apply_product_ad_creation explicitly.

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 phrases 'immutable, separately confirmable' and 'persists an internal plan' imply this is a prepare step before confirmation/apply, but the description never states when to use this tool versus apply_product_ad_creation or confirm_workflow_plan. The usage context is inferable but not explicit.

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