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

Annotations already establish readOnlyHint=true and destructiveHint=false, so safety is covered structurally. The description adds genuinely non-obvious context: SP-API does not expose real remittances in read mode, so the returned figures are estimates derived from purchase orders rather than actual remittance data. That caveat materially affects how an agent should interpret and present the results.

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 tight sentence with the important caveat front-loaded after the resource name; nothing is padded. It is very short, but every clause carries meaning, so the brevity is an asset rather than under-specification at the sentence level.

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?

With no output schema, no annotations beyond the safety hints, and two of three parameters undocumented, the description leaves material gaps: what fields the estimates contain, how days_back bounds the PO set, and what summary_only changes. The one caveat it does provide is valuable but does not cover this surface.

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 is documented in the schema, but days_back and summary_only have no description anywhere, and the description does not compensate by explaining what a day window means here or what summary_only suppresses. The PO-based framing hints that the figures derive from a PO window but never ties this to days_back explicitly.

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 names a specific resource (vendor remittance amounts) and scopes it to values estimated from POs, which is more than a restatement of the name. However, it gives no verb (list vs compute vs estimate), and it does not distinguish itself from close siblings like get_vendor_invoices or get_vendor_po_summary, so an agent still has to guess which vendor-money tool to pick.

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?

There is no when-to-use guidance and no named alternative. The parenthetical caveat explains a limitation of the data source but does not tell the agent when this tool is the right choice versus get_vendor_invoices, get_vendor_po_summary, or get_vendor_purchase_orders.

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