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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the write-safety profile is covered. The description adds real behavioral detail the annotations lack: the MANUAL default, the 0-900% placement-bid bound, and the allowed strategy values. However it never mentions the preview/confirm two-step write flow that the confirm_id parameter implies, which is the most consequential behavioral fact for an agent calling this tool.

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?

Front-loaded with the one-line purpose, then a dense but single-topic paragraph of parameter guidance. Every clause carries information, but the run-on structure and mixed Italian/English phrasing make it slightly harder to scan than it needs to be.

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 mutation tool with no output schema and a nested campaign object, the description covers the branching workflow, placement bidding, strategy, and portfolio assignment well. Its notable omission is the preview-then-confirm write protocol, which is left entirely to the schema's confirm_id description; an agent reading only the description could miss it.

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 67% and the description more than compensates: it supplies the placement enum values (PLACEMENT_TOP|PLACEMENT_PRODUCT_PAGE|PLACEMENT_REST_OF_SEARCH|SITE_AMAZON_BUSINESS) and the 0-900% range for percentage, plus the dynamic_bidding.strategy enum, none of which appear in the schema (dynamic_bidding is an untyped object and placement has no enum). It also states the MANUAL default for targeting_type, which the schema does not.

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 opening sentence gives a specific verb+resource ('Create a SP campaign') that is immediately distinguishable from siblings like ads_create_sp_ad_group or ads_create_sp_keywords. The rest of the description stays scoped to creation and never drifts into update/delete territory.

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?

It explicitly routes the agent through the two targeting modes and names the follow-up tools for each (ads_create_sp_keywords for MANUAL keywords, ads_create_sp_product_targets for AUTO/ASIN), including the explicit exclusion 'NON aggiungere keyword/target manuali' under AUTO. It stops short of naming a true alternative to this tool (e.g., when to prefer ads_update_sp_campaign instead), so it is strong context rather than a full when/when-not matrix.

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