subscriptions_promoted_purchase_get_to_one_related

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

There are no annotations, so the description carries the full disclosure burden, and it discloses essentially nothing beyond the HTTP verb implying a safe read. It does not say what happens when no promoted purchase exists, whether relationships must be included to get data, or anything about authentication or rate limits. The only behavioral signal is the incidental word GET.

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?

It is short, but the content is duplicated verbatim in parentheses, so half the text is pure waste. The problem is under-specification rather than length: an agent gets no front-loaded statement of effect or return.

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?

A 5-parameter tool with sparse filtering semantics, no output schema, and no annotations needs the description to explain the response shape and the effect of include/fields_*. Instead the description is a URL, leaving the caller to infer how to build a valid request beyond the required id.

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%, and each of the 5 parameters (id, include, and the three fields_* filters) is documented in the schema, so the baseline of 3 applies. The description adds no meaning beyond the schema - notably it never explains that include/fields_* shape the returned payload, which is the one thing worth adding here.

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 is only the raw route restated twice: "GET /v1/subscriptions/{id}/promotedPurchase (GET /v1/subscriptions/{id}/promotedPurchase)". It tells an agent this is a read of the promoted purchase tied to a subscription, but it does not explain what a promoted purchase is or how this differs from the near-identical sibling subscriptions_promoted_purchase_get_to_one_relationship. That is a restatement of the name, not a statement of purpose.

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?

No when-to-use guidance is given. The tool list contains an almost indistinguishable sibling (subscriptions_promoted_purchase_get_to_one_relationship) plus in_app_purchases_v2_promoted_purchase_get_to_one_related, yet the description offers no rule for choosing among them. Nothing is misleading, but nothing guides selection either.

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