Create newsletter list subscriber import

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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=false, so the mutation profile is covered. The description adds genuinely non-annotated facts: it changes account state, the confirm flag must be set, and the OAuth scope newsletter_lists:write is required. It stops short of describing the import's effects (which subscribers end up added) or its asynchronous nature.

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, no filler, with the core action front-loaded before the confirm and auth constraints. Efficient, though the sentences read as stacked constraints rather than a tightly organised statement.

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 destructive, non-idempotent, eight-parameter tool with a nested payload object and no output schema, the description covers the confirm/auth essentials but omits the import lifecycle. The sibling newsletter_list_subscriptions_get_import implies an import resource with an ID and status, which an agent would want to know before invoking, and that is nowhere stated.

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% and all eight parameters, including the nested payload and the tag/custom_field_id mutual exclusion, are documented in the schema itself. The description surfaces only confirm=auth, adding no semantics beyond what structured fields already carry, so the baseline of 3 applies.

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 ('Create newsletter list subscriber import'), so an agent knows exactly what entity is being produced. It does not differentiate from near-neighbours such as create_newsletter_list_subscription, create_bulk_subscription, or create_subscription, which is the only thing keeping it out of the top band.

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 gives one real gating condition (confirm=true for the user-requested action) and an auth requirement for OAuth integrations, which is useful context. It never says when to prefer this import path over the plain subscription-creation siblings, so selection guidance is only implied.

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