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 covered. The description adds nothing about overwrite semantics, what happens to fields left null, or whether the update is reversible — the key behavioral questions for a destructive partial-update tool with six optional nullable params.

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?

One front-loaded sentence with no filler; the updatable fields appear immediately. It is efficient, though the terseness borders on under-specification for a 7-parameter mutation.

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, seven-parameter mutation with no output schema and zero schema documentation, the description should explain the remaining parameters and the null/omitted-field behavior. It covers less than half the surface an agent needs to call this correctly.

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 7 parameters, so the description must compensate and does not. It mentions only margin, amount, and contract price, leaving marginType, franchisePercentageMargin, intentId, and externalLedgerCode entirely unexplained.

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 verb (update) plus the resource (customer-specific rate) and the mutable fields, which distinguishes it from the sibling UpdatePartnerRate and pairs naturally with AddCustomRate. It is clear, though it does not explicitly call out the sibling 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?

"on an existing customer-specific rate" implies the prerequisite (a rate must already exist, so use AddCustomRate to create one), but there is no explicit when-to-use vs when-not guidance or reference to UpdatePartnerRate/AddCustomRate by name.

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