Add a free trial

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

Annotations already declare idempotentHint=true, destructiveHint=false, openWorldHint=true and readOnlyHint=false; the description adds value beyond them by naming the required credential (ASC_WRITE=1), disclosing that it runs as a resumable bulk job with progress, and explaining the mechanism behind idempotency ('steps already done are skipped'). It stops short of noting rate limits, partial-failure reporting, or what a resumable job returns, so it is strong but not exhaustive.

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 sentences, front-loaded with the core action and scope, then the paid-offer exclusion, then the environment/permission caveat. Dense and largely waste-free, though the parenthetical '(or the ones you list)' is mildly redundant with the territories parameter.

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 7-parameter mutation with no output schema, the description covers the essential agent-facing facts: write permission needed, idempotent/resumable behavior, territory defaults, and the sibling to use instead. The remaining gap is that start_date/end_date semantics and their interaction with the offer window are left entirely to an undocumented schema.

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 57%: app, territories, dry_run and subscription carry their own descriptions, and the description's territory scoping largely restates the schema's 'Default: every territory the subscription is available in.' However, start_date and end_date have no description in either place, and the duration enum values are unexplained, so the description does not compensate for the remaining coverage gap.

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 ('Adds a free-trial introductory offer to a subscription') plus the scope (every territory where it's sold, or listed ones). It is clearly distinguishable from remove_intro_offers and from the generic asc_request sibling it names.

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?

Explicitly routes the agent: free trials go here, paid introductory offers 'aren't covered; use asc_request for those'. It also states the skip condition (territories that already have an introductory offer), so both when-to-use and when-not-to-use are covered.

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