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

No annotations are provided, so the description carries the full burden of behavioral disclosure for a mutation tool. It discloses one precondition on organisationId, but says nothing about side effects, what happens on duplicate/conflicting rates, required permissions, or whether the operation is reversible.

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 action and the key precondition, with zero filler. It is efficient, though for a 9-parameter mutation the brevity shades into under-specification rather than tightness.

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?

Given a complex 9-parameter, 5-required mutation with no annotations and no output schema, the description is far too thin. It omits how the many numeric/string parameters interact and what the call returns or affects, leaving significant gaps an agent would need filled.

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% across 9 parameters, so the description must compensate and largely does not. It only addresses organisationId (and its customer constraint); the meaning of marginType, amount, contractPrice, carrierContractId, carrierRouteId, and franchisePercentageMargin is left entirely undocumented.

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+resource ("Add a customer-specific shipping rate") and the qualifier "customer-specific" meaningfully distinguishes it from the sibling AddPartnerRate. It stops short of explicitly naming alternatives, but the resource and scope are unambiguous.

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 one useful precondition (organisationId must be a customer of this partner), but no explicit when-to-use guidance and no routing to alternatives like AddPartnerRate, UpdateCustomRate, or AddPartnerSurcharge. The agent must infer the distinction from the word "customer-specific" alone.

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