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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: the supported stock regions, the full set of possible status values, and that 'out-of-stock-replenishable' comes with a replenishment date. It stops short of describing response shape, ordering, or partial-failure behavior.

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 dense, front-loaded sentences with no filler; the status enumeration is the load-bearing content and comes first. Including the raw endpoint path 'POST /v3/stock/region-availability' is the only element of questionable value to an agent, but it is a single clause.

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 partially carries the return-value burden by enumerating possible statuses and noting the replenishment date, and it names the batching limit range via the schema. It still omits how results map to the input UIDs and what happens on invalid/non-stockable UIDs, but for a single-parameter read tool it is largely complete.

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% (product_uids: 'Gelato product UID.' with bounds 1-250), so the schema fully documents the sole parameter. The description adds no syntax, format, or UID-source guidance, so the 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 ('Stock status of stockable products per stock region') and enumerates the exact outcome taxonomy (in-stock, out-of-stock-replenishable, out-of-stock, non-stockable, not-supported), so an agent knows precisely what the call returns. No sibling tool touches inventory, so it is trivially distinguishable from the order/product/pricing siblings.

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?

The description says what the tool reports but never when to call it (e.g., before create_order/quote_order to avoid unfulfillable items) nor what alternatives exist. No prerequisites, no exclusions, no workflow context — the agent must infer the use case entirely.

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