Add subscriber to form

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

Annotations already declare destructiveHint=true and idempotentHint=false, so safety is partly covered. The description adds genuine context beyond them: the categories of side effect (delivery, audience membership, published data, irreversible state) and the mandatory confirm=true gate.

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 short sentences with no filler, and the required precondition is front-loaded in the first sentence. Nothing wasted.

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 mutating tool with a nested payload object, the description covers the critical safety gate and effect scope, while the rich schema handles the rest and no output schema exists to explain. The only real gap is sibling disambiguation, which is minor.

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 86%, so the schema already documents almost every parameter including the payload/payload_file mutual exclusion. The description adds only the confirm=true requirement, which the schema also states, so it does not meaningfully go beyond the structured fields.

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 ('Add subscriber to form'), which is clear on its own. However, it does not distinguish itself from the near-identical sibling 'add_subscriber_to_form' (the name suffix '_by_id' is the only hint), so the agent has to infer the difference from naming 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?

Gives one concrete prerequisite ('Requires confirm=true'), which is actionable. It does not say when to prefer this over 'add_subscriber_to_form' or 'bulk_add_subscribers_to_forms', leaving the sibling selection implied.

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