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

Annotations declare a read-only, non-destructive, closed-world call, but the description adds the crucial behavioral fact the annotations cannot convey: this tool is a no-op stub explaining an SP-API limitation rather than returning data. That is exactly the kind of context an agent needs to avoid misusing it.

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?

A single dense sentence front-loads the limitation and then the redirection, with zero filler. Nothing about the tool's nature is deferred or buried.

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 stub/explanation tool with no output schema, the description covers what matters: why it exists and where to go instead. The remaining gap is that it never says whether the optional parameters change the explanation text or are simply ignored.

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 only 33% (account_id documented, days_back and ship_from_party_id not) and the description explains none of the three parameters. With low coverage the description is expected to compensate, and it offers no syntax, meaning, or default for any parameter.

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 exactly what the tool returns: not invoice data but an explanation of why SP-API exposes no vendor retail invoice read endpoint (only POST submitInvoices). It also names the sibling to use instead, so the agent can distinguish it from get_vendor_remittances and get_vendor_purchase_orders without opening a schema.

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 explicitly routes the agent: get_vendor_remittances for estimated amounts and Vendor Central for the actual invoices. Both the alternative and the condition that selects it are named, leaving nothing to inference.

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