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

No annotations are provided, so the description carries the full burden. 'Add' implies a mutation, but nothing is disclosed about permissions, whether the rate can be modified afterward, side effects, or validation failures for an 8-parameter write operation.

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?

Three short sentences, front-loaded with the action and scope, then the two most error-prone values. No filler; efficient for its size.

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 mutation tool with no annotations, no output schema, and 8 undocumented parameters, the description is far too thin. It omits prerequisites, expected results, and the meaning of most required inputs.

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 0% for 8 parameters, yet the description only clarifies two: marginType (sample values FixedAmount/Percentage) and carrierRouteId (how to obtain it). The remaining six, including required carrierContractId and amount, carry no meaning anywhere.

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 (Add) and resource (partner shipping rate), and the parenthetical '(not customer-specific)' distinguishes it from the AddCustomRate sibling. Clear and specific, though it could name the sibling directly for a stronger contrast.

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?

Provides one concrete usage aid ('Find carrierRouteId via get_carrier_routes') and bounds scope via the parenthetical, but never states when to prefer this over AddCustomRate or UpdatePartnerRate. Usage is implied rather than explicit.

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