my_fulfilment_selection

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

With no annotations, the description carries the full behavioral burden; it does disclose the auth requirement, which is the most important trait for a user-scoped endpoint. It says nothing further about read-only nature, whether a missing selection yields null/empty, or caching, so it leaves meaningful behavioral gaps.

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 short sentences, front-loaded with the resource and followed by the precondition. Slightly redundant, since 'signed-in user's' already conveys the login requirement that the second sentence restates, but nothing is wasteful enough to obscure the point.

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-value details need not be described, and a zero-parameter call is inherently simple. Still, the definition never clarifies what a 'fulfilment selection' actually is in this domain (delivery vs. pickup mode, store binding) or how it differs from the similarly named sibling, which is the main unresolved ambiguity.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly implies no inputs are needed.

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 ('fulfilment selection') and scopes it to the signed-in user, which distinguishes it from the sibling 'fulfilment_selection'. However, it is a bare noun phrase with no verb, so an agent must infer that this is a read operation returning the current selection rather than, say, a setter or a status check.

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?

'Requires login' is a genuine usage precondition and implies the tool should only be called in an authenticated context. Beyond that, there is no guidance on when to prefer this over the sibling 'fulfilment_selection', nor what happens if the user has not yet made a selection.

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