Add subscribers

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

The description substantially expands on annotations: it explains that the request body is a top-level JSON array, warns that preserving existing entries matters, clarifies that PUT is the real method despite a Python sample using POST, and discloses side effects such as notifying recipients or changing tenant data. This is valuable beyond the raw 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?

The description is compact and front-loads the action and endpoint. Each sentence adds a relevant caveat or requirement, though the 'Body fields: recipients' fragment feels slightly abrupt and the official-operation note is redundant with the reference link.

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?

Given the mutating nature, generic body schema, and lack of output schema, the description covers method, body shape, confirmation requirements, destructive side effects, and preservation behavior. It does not describe response format or recipient entry fields in detail, but the official reference and imperative to consult the operation close most of the gap.

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?

The schema is generic for body and high-level for confirm, but the description adds needed meaning: the body is a top-level array and the listed body fields describe array entries rather than root keys. It also names 'recipients' and links to official documentation. It leaves recipient field shapes somewhat vague, but it compensates beyond the schema baseline.

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 opens with 'Add subscribers' and pinpoints the exact REST operation: PUT /api/xm/1/subscriptions/{subscriptionId}/subscribers. This identifies the specific resource and action, and the endpoint distinguishes it from sibling tools such as get_subscribers, unsubscribe_a_user, and create_a_subscription.

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 gives clear context for when this tool is appropriate: adding subscribers to a subscription, with an explicit requirement for operator write opt-in and confirm:true. It does not explicitly name alternative tools or state when not to use it, but the operation and prerequisites are clear enough.

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