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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the description is not obligated to restate that this is a safe read. It adds value by naming the backing endpoint (GET /api/Inventory/GetInventoryItemById) and by listing the returned fields, but says nothing about not-found behavior, authorization, or rate limits.

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 tight clauses with zero waste, and the retrieval purpose is front-loaded before the field enumeration and endpoint reference. Nothing is padded or repeated from structured fields.

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?

There is no output schema, so enumerating the product attributes (SKU, barcode, quantities, prices, tax rate, category, dimensions, weight) is genuinely useful context. The only real gap is error/empty-result behavior for an unknown stock item id, which the agent would have to discover at call time.

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% and the schema already documents the UUID pattern and tells the agent to source the id from linnworks_search_inventory. The description's 'by its stock item id' adds no syntax or format detail beyond the schema, 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 and resource ('One product by its stock item id') and enumerates the returned attributes, making clear it is a single-item fetch rather than a search. An agent can distinguish it from linnworks_search_inventory on scope alone, since the singular 'one product by id' contrasts directly with a search that returns a list.

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?

Usage is only implied: fetch an item when you already hold a StockItemId. The description never states when to prefer this over linnworks_search_inventory or linnworks_get_stock_levels, and no exclusions are given. The pointer to search_inventory lives in the schema parameter description, not the tool description itself.

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