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

Annotations already cover the safety profile (readOnly, non-destructive), yet the description adds meaningful behavior: the type decides which leg is read and a wrong value fails, sibling-leg returns for send/receive transfers, and stockTransferId being the input receive_stock_transfer needs. It even disambiguates that quantities are amounts MOVED at creation, not current stock — genuinely useful beyond structured fields.

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-loads the core outcome (one transfer in full) before the mechanics of the type argument and the quantity caveat. Dense but each clause carries a distinct fact; only slightly long, but nothing is 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?

With no output schema, the description carries the full burden of describing return contents and it does so thoroughly (outlets, employee, invoice, notes, line items, sibling leg, stockTransferId). Combined with the readOnly annotations, an agent has everything needed to call and interpret it correctly.

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 real semantics: transactionId and type must be passed exactly as get_stock_transfers returned them, and the type selectively determines which leg is fetched. That is more than the enum/schema restates.

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 (retrieve a single stock transfer in full) and enumerates the returned contents — both outlets, employee, invoice, notes, line items with quantities. It clearly distinguishes itself from the plural hub_get_stock_transfers (list source) and hub_get_stock (current stock), so an agent can tell them apart without opening schemas.

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 concrete context: the type value must come from get_stock_transfers, and it explicitly redirects to get_stock for current stock levels. It also explains the downstream use of the returned sibling leg and stockTransferId for receive_stock_transfer. It doesn't explicitly state the when-to-prefer-this-over-list condition, keeping it just short of a 5.

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