create_lead_sync_subscription

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

No annotations are present, so the description carries the behavioral burden. It does more than say 'create': it states that leads will be POSTed and signed with Standard Webhooks HMAC, and it requires an idempotency key—core operational behavior an agent needs. It stops short of describing duplicate-key semantics or the response, but these are secondary for selecting and invoking the tool.

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 sentences, front-loaded with purpose, followed by prerequisites and delivery behavior. Every sentence earns its place; there is no filler, and the most important information appears first.

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?

The description gives enough to start a call: required key and URL, plus the post-creation delivery behavior. However, it does not explain how to supply the ad account when both ad_account_id and ad_account_ids are optional, nor what the tool returns. Without an output schema or annotations, these gaps make the definition adequate but not fully complete.

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?

Three of four parameters have schema descriptions, so the baseline is 3. The description adds no per-parameter meaning beyond the schema and leaves the undocumented ad_account_id ambiguous relative to ad_account_ids. Restating the required Idempotency-Key and destination URL duplicates the schema rather than adding value.

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 uses a specific action ('Provision') paired with a clear resource ('lead delivery to a managed webhook endpoint for an ad account'). This makes the creation intent unmistakable and distinguishes it from the sibling list/get/delete subscription tools and from lead-form tools. There is no ambiguity about what resource is acted on.

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 clearly states the use case—delivering leads to a webhook endpoint—and gives actionable prerequisites: an Idempotency-Key and a destination URL. It does not explicitly name alternatives or when-not-to-use conditions, but the context is strong enough for an agent to decide when this tool is appropriate.

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