fulfilment_selection

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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose one genuine behavioral trait the schema does not: when no postcode is supplied, the tool resolves against the guessed location rather than failing. However, it says nothing about whether this is a read-only lookup, what triggers the different fulfilment modes, whether results are cached or scoped to the session, or about permissions.

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?

The fragment is short and front-loaded, so it is efficient. But it is compressed to the point of ambiguity: the colon-separated "cooperative, warehouse, slot" reads as an unfinished enumeration with no framing verb, costing more clarity than the brevity saves.

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 tool with zero annotation coverage, 0% schema description coverage, and heavy overlap with a large set of fulfilment/location/delivery siblings, the description does too little. An output schema exists, so return values need not be explained, but the routing information an agent needs to choose this tool over delivery_info or my_fulfilment_selection 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 description coverage is 0% for the single zip_code parameter, so the description must compensate. It labels the parameter as a postcode and explains that omitting it falls back to a guessed location, which is real meaning beyond the bare nullable string in the schema. It does not specify format expectations (postal code vs. country prefix) or how an incorrect postcode is handled.

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 identifies the resource as "delivery context for a postcode" and hints at the returned dimensions (cooperative, warehouse, slot), so the general area is graspable. But there is no verb and no statement of what the tool actually does with that context, and the trailing list is too terse to be certain whether those are returned mode types or input options. It is not distinguished from close siblings such as delivery_info, my_fulfilment_selection, or checkout_timeslots.

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?

There is no when-to-use guidance at all: no statement of which situations call for this tool versus delivery_info, store_availability, checkout_timeslots, or my_fulfilment_selection. The parenthetical "or the guessed location" hints at a fallback but not at when the caller should pick this tool over the alternatives.

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