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

Annotations declare non-read-only, non-destructive, closed-world, and the description adds real context beyond them: the plan is immutable, persisted internally, and has no effect on live advertising entities until separately confirmed. It does not quantify plan lifetime or confirm permissions, keeping it below a 5.

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, each carrying distinct information – what it does, its scope, and its side-effect profile – with the key differentiator (immutable, confirmable plan) front-loaded.

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?

An output schema exists and the nested schema carries the heavy parameter documentation, so return values and field semantics are covered. What remains missing for a multi-step workflow tool is the explicit next action (confirm_workflow_plan / apply_campaign_creation), though 'separately confirmable' points in that direction.

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 coverage is 100% and the nested schema already documents every field, so the baseline is 3; the description adds meaning by explaining adProduct is reserved for future Sponsored Brands/Display, that targetingType controls automatic target creation on execution, and that the server derives marketplace fields. It does not add field-level syntax beyond that.

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?

Names a specific verb and resource (prepare an Amazon Ads campaign plan for Sponsored Products) and distinguishes planning from execution with 'without changing advertising entities.' The middle sentence 'Creates Sponsored Products campaigns' is momentarily misleading for a prepare tool, but the surrounding sentences scope it to a plan.

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?

Implies the two-step flow via 'immutable, separately confirmable plan,' but never names apply_campaign_creation or confirm_workflow_plan as the follow-up, nor states when to use this instead of apply_campaign_creation. Usage must be inferred from the sibling naming pattern.

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