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 risk profile is partly covered. The description still adds real value by naming the affected surfaces (delivery, audience membership, published data, irreversible state) and disclosing the confirm=true gate, which is not derivable from 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?

Three short declarative sentences with zero filler; the core action leads and the risk/confirm constraint follows immediately. Nothing needs trimming.

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?

With no output schema and full schema coverage, the description need not explain return values, and the annotations carry the safety profile. It covers the action, the impact and the confirm gate adequately, though it omits whether re-adding an existing subscriber errors or is a no-op and what a successful result looks like.

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 account, confirm, sequence_id and subscriber_id are all documented in the schema itself. The description only restates the confirm requirement, adding no syntax, format or defaulting nuance beyond the schema, 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?

Names a specific verb and resource (add subscriber to sequence), so the operation is unambiguous. However, it does not distinguish itself from the near-identical sibling add_subscriber_to_sequence (the by_id vs email variant), leaving the agent to infer the difference from the tool name alone.

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?

States the precondition 'Requires confirm=true', which is actionable context. But it gives no guidance on when to pick this tool over add_subscriber_to_sequence or add_subscriber_to_form, and no exclusions, so usage is only implied.

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