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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is known. The description adds almost nothing beyond that: it does not say whether this is a partial update, whether omitted fields are left untouched, or what side effects the destructive hint implies.

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?

The single sentence is front-loaded and free of filler. It is appropriately brief, though its brevity contributes to the parameter and behavioral gaps rather than resolving them.

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 destructive mutation with seven parameters, zero schema descriptions, and no output schema, the description is too thin. It should at minimum clarify the partial-update semantics and identify the undocumented parameters.

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 parameter meaning, but it only names margin, amount, and contract price. Four parameters (marginType, franchisePercentageMargin, externalLedgerCode, intentId) are left completely undocumented in both schema and description.

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 states a specific verb (Update) and resource (partner rate) and bounds the target with '(no customer)', which helps separate it from customer-oriented rate tools. It does not name any sibling such as UpdateCustomRate or UpdatePartnerSurcharge, so differentiation is only partial.

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 no explicit guidance on when to choose this over UpdateCustomRate, UpdatePartnerSurcharge, or AddPartnerRate. The parenthetical '(no customer)' hints at scope but does not give the agent a decision rule or any preconditions for use.

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