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

Annotations only cover the safety profile (readOnly, non-destructive), and the description goes well beyond that: it discloses that outletId restricts results to stock-tracked items and adds an onHand field, that an item absent from the list simply is not linked yet, and what each row carries. That is real operational context an agent cannot get from the annotations.

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?

Front-loaded with purpose before workflow guidance, and each sentence carries distinct information (purpose, ordering, outletId behavior, fallback path). It is on the dense side at five sentences, but nothing reads as filler.

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?

For a read-only list tool with no output schema, the description supplies the missing return-shape information (cost, part number, onHand), the parameter-dependent behavior, and the workflow position relative to create_purchase_order and link_supplier_items. Nothing needed to call it correctly is absent.

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 the baseline is 3, but the description adds genuine meaning beyond the schema for outletId (why to pass it: narrowing to stock-managed items and adding onHand) and confirms search/paging behave identically with or without it. supplierId's 'not a name' constraint is already in the schema, so credit is limited to the outletId explanation.

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 ('the catalogue items one supplier carries') and immediately enumerates the payload that matters: merchant cost and supplier part number. It also contrasts implicitly with hub_get_linkable_items and hub_get_suppliers by framing what this list does and does not contain.

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?

Explicit preconditions and routing: 'CALL THIS BEFORE create_purchase_order', 'PASS outletId when you are about to build an order', and a named fallback path ('get_linkable_items then link_supplier_items') for items that are missing. This tells the agent when to use it, when to pass an extra parameter, and what to do instead.

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