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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful context: the recipient enters their own delivery details and payment, and agents cannot place orders. This is useful workflow/boundary disclosure beyond the annotations, though idempotency and link behavior are left to 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?

A single dense sentence, front-loaded with the artifact and effect, followed by the workflow constraint. No filler or redundancy.

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 and a single simple param, the description covers the essential purpose and the key operational boundary (agents cannot check out). It omits any hint of the returned link/format, which is a minor gap.

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%, so the description must carry the weight, and it only loosely ties the 'items' param to 'already in it.' It does not explain that items are variant_id/qty pairs or any format constraints, but the single param is largely self-describing from the schema.

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 names a specific artifact (a deer.supply cart link) and its effect (opens the cart pre-filled with the given items). It clearly conveys the resource and outcome, though it never names a sibling like quote_cart to sharpen the boundary.

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 implied: the link is for the person to review and check out themselves, and 'Agents cannot place orders' sets a boundary on agent behavior. However, there is no explicit when-to-use-this-vs-alternatives routing (e.g., when to use this instead of quote_cart).

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