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

With no annotations, the description carries the full behavioral burden. It discloses the content of the return (all attributes plus per-destination status and issues), which is useful, and the account param implies a read-only fetch. But it never explicitly states that it is a non-mutating read, nor mentions auth/permission needs or any rate limits.

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 front-loaded sentences that open with the resource and payload, then the identification options. No filler. The parenthetical attribute list is somewhat long but serves to convey payload breadth.

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 single-record getter with no output schema and no annotations, the description covers what the resource is, what it returns, and how to address it. The main remaining gap is the lack of explicit read-only confirmation, but overall it is complete enough to call correctly.

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 100%, so the baseline is 3, but the description adds real meaning: it explains the two alternative ways to identify the product (product name from merchant_products vs offer id + language + feed label). That relational guidance goes beyond the schema descriptions and clarifies that both identification paths are mutually exclusive destinations.

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 states a concrete resource (one product in Merchant Center) and enumerates what it contains (attributes, status, issues per destination), so an agent knows this is a single-product fetch. It distinguishes itself from merchant_products (list) by describing the singular scope. It could be sharper about the verb (get/read) and its relationship to merchant_status, which also covers status/issues.

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 gives usage for input construction — identify the product by `product` from merchant_products, or by offer id with language and feed label — which is genuinely helpful routing. However, it never states when to use this tool versus merchant_products, merchant_status, or merchant_report. Usage is implied by the family workflow rather than explicit.

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