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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new context: the auth/store-connection requirement and the sign-in prompt behavior, which the annotations do not express.

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 sentences, zero filler, with the triggering condition front-loaded ahead of the returned-field list and the prerequisite. Every clause carries information an agent needs.

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?

An output schema exists so return values need no explanation, and the description still summarizes the key fields plus the auth prerequisite. Minor gap: no mention of what happens for an unmatched SKU (error vs empty), which matters for an exact-match lookup.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents 'sku' as the exact merchant SKU code. The description reinforces the exactness requirement ('names an exact SKU'), adding a little meaning, but nothing about format or case sensitivity beyond the schema — baseline 3.

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 and enumerates the exact data returned (live stock, forecast demand, days of supply, reorder point, suggested quantity, supplier, open-PO coverage). The phrase 'the merchant names an exact SKU' implicitly separates it from the search-style sibling find_inventory_items, though that sibling is never named.

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?

Gives a clear triggering condition ('when the merchant names an exact SKU') plus a prerequisite ('requires a connected Forthcast store; the assistant will prompt to sign in'). It does not explicitly say when not to use it or name find_inventory_items/get_inventory_overview as alternatives, so it stops short of full when/when-not guidance.

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