cart_set_shipping_method

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

With no annotations, the description carries the full burden for a mutation. It does not disclose what happens if a method is invalid for the shop, whether an existing selection is overwritten, whether totals/prices change, or what the call returns. Only the verb 'Select' implies mutation.

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 front-loaded sentence with no filler. The example values largely duplicate the schema's own examples, which is minor redundancy but not wasteful enough to penalize further.

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 state-changing cart tool with no annotations and no output schema, the description omits error behavior, validation against shop-specific methods, and any note on effect on cart state or totals. An agent can attempt the call but cannot anticipate failure modes.

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 100% and both parameters are documented there, including the shop enumeration and shipping-method examples. The description adds no format constraints, valid-value lookup, or resolution rules beyond what the schema already states, so baseline 3 applies.

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 uses a specific verb ('Select') with a clear resource ('shipping or pickup method for a store cart') and even supplies example values. It is unambiguous on its own, but it does not name or reference any sibling cart tools to sharpen the boundary (e.g. vs. cart_add_item or cart_view).

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?

It never states when to call this versus alternatives, nor any preconditions such as the cart needing items or needing a prior cart_view to discover the valid method IDs for a given shop. The agent must infer the workflow entirely.

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