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

No annotations are provided, so the description carries the full behavioral burden. It does not state that rateId is required, whether unspecified fields are preserved, whether the change is reversible, what permissions or auth are needed, or what the response looks like. For a mutation tool with zero annotation coverage this is a substantial gap.

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 short, front-loaded sentence with no filler; the verb and target resource lead. It is appropriately sized for a single-purpose update tool, though it could add a clause about the required rateId at no cost.

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?

A 7-parameter mutation tool with no annotations, no output schema, and 0% schema description coverage needs a much richer description to be callable correctly. The current text leaves most parameters and all behavioral context undocumented.

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. The description names only three updatable fields (margin, amount, contract price) and leaves rateId, intentId, marginType, externalLedgerCode, and franchisePercentageMargin completely unexplained 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?

States a specific verb ('Update') and resource ('existing customer-specific rate'), and enumerates which fields can change. It implicitly distinguishes itself from siblings UpdatePartnerRate and UpdatePartnerSurcharge by scoping to customer-specific rates, though it never names them.

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?

No when-to-use guidance, no prerequisites, and no mention of the closely related UpdatePartnerRate / UpdatePartnerSurcharge tools. The agent must infer from the tool name alone that this applies only to custom (customer-specific) rates.

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