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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description earns extra credit for disclosing the severe 5/min throttle, which materially affects how an agent should sequence calls, and it names the underlying endpoint.

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?

Three sentences, zero waste, with the payload shape front-loaded and the throttling constraint placed prominently after it.

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, the description does state what comes back (quantity per SKU plus last-modified time) and warns about rate limits. It stops short of describing the response envelope or how pagination cursors (next.page/next.skip) are surfaced, which matters for a heavily paginated read.

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 pagination semantics (page/skip/limit/page_size) are already fully documented in structured fields. The description only adds the intent behind modified_after; it says nothing about modified_before or expand_alternate_skus beyond the schema. Baseline 3 applies.

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?

States a specific verb+resource: sellable quantity per SKU across all warehouses, plus last-modified time. That scope implicitly separates it from sibling get_warehouse_quantities and get_inventory_by_location, but no sibling is named explicitly.

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?

One concrete usage hint is given ('Use modified_after to see only what changed'), which tells the agent how to do incremental sync. There is no guidance on when to prefer this over get_item_quantities or get_warehouse_quantities, so selection among siblings is left to inference.

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