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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true), but the description adds real behavioral context beyond them: the campaign is created in PAUSED state and confirm=false triggers a dry-run. These are meaningful operational traits an agent needs.

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?

Extremely terse and front-loaded: verb+resource first, then parameter clarifications, then dry-run behavior. Every clause carries information, though the telegraphic style borders on under-specification for a 7-parameter write tool.

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 so return values need no explanation. However, for a mutation tool creating a campaign with required budget and targeting-adjacent params, the description says nothing about budget units, target_cpa meaning, or the customer_id scope, leaving gaps an agent would need to guess at.

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 7 parameters, so the description must compensate. It clarifies three parameters (app_id as store app ID, app_store enum values, confirm dry-run semantics) but leaves name, customer_id, daily_budget, and target_cpa unexplained. Partial compensation.

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: 'Creates an App (UAC) campaign'. The 'App (UAC)' qualifier distinguishes it from sibling campaign creators like create_search_campaign, create_demand_gen_campaign, and create_pmax_campaign, though it does not name them 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?

Usage is implied by the brief operational notes (dry-run via confirm=false, created PAUSED), but there is no explicit when-to-use or when-not-to-use guidance relative to the many other create_*_campaign siblings. An agent must infer platform routing from 'App (UAC)'.

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