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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered; the description adds genuinely non-obvious behavior: rows are account/region-level and 'surface tenant-wide for any key', plus snapshot_date meaning 'when a row was last refreshed'. That scoping caveat materially affects how results should be interpreted, though nothing is said about rate limits or result size.

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?

Four sentences, front-loaded with purpose and the core metric, then usage, then scoping caveats. Slightly over-explained with mild redundancy between 'Returns the current state of each shipment's items' and the shipped-vs-received framing, but nothing is padded.

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 an output schema present and all 8 parameters documented at 100%, the description only needs to cover interpretation caveats — and it does: freshness semantics, the shipped-vs-received comparison, and the tenant-wide scoping behavior. An agent has everything needed to call and read this tool 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 description coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks: snapshot_date is explained as freshness/refresh time, and the tenant-wide scoping note clarifies that sku/shipment_id filters do not narrow results to a single tenant. This goes beyond restating schema text.

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 verb+resource ('Get per-SKU receiving status for FBA inbound shipments') and pins down the exact metric returned ('quantity shipped vs quantity received by Amazon'). That precision implicitly separates it from near-siblings such as get_fba_inbound_operation_status and get_inbound_shipments without needing to name them.

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?

'Use to track receiving progress and identify discrepancies' provides an implied usage context but is essentially a restatement of the purpose. No when-not-to-use condition and no routing to competing siblings (operation status, inbound shipments) is offered, so selection still requires inference.

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