Add subscriber to sequence

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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds value by enumerating the affected surfaces (delivery, audience membership, published data, irreversible state) and the confirm=true requirement, which is not expressed in the annotations.

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?

Two tight sentences with the effect warning and the confirm requirement front-loaded. No filler, nothing redundant.

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, open-world mutation with no output schema, the description conveys the risk surface and the confirmation gate. It omits what success/failure returns and whether the operation can partially apply, which would help, but the core call requirements are present.

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%, so the schema already documents account, confirm, sequence_id, and subscriber_id. The description only restates the confirm requirement and adds no syntax or format detail beyond it — baseline 3.

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 the exact verb (Add) and resource (subscriber to sequence), and the '_by_id' suffix plus sibling 'add_subscriber_to_sequence' implies an id-based variant. An agent can distinguish this from the email-based sibling immediately.

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?

The description gates the action behind confirm=true, implying it should only be used when explicitly requested. However, it never names the sibling 'add_subscriber_to_sequence' or explains when to prefer the id variant over the email variant, leaving that choice to inference.

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