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

The annotations already establish the tool as read-only, idempotent, and non-destructive, so the description does not need to restate safety. It adds useful context by saying the estimate uses current assumptions, signaling open-world dependence and that results may change as the underlying index assumptions change.

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?

A single, focused sentence front-loads the verb and object, and every phrase contributes to the core meaning. It is appropriately sized for the tool's simplicity.

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 the rich annotations, an output schema, and simple parameters, the description plus schema gives an agent enough to call the tool safely. It is slightly less complete on parameter semantics, but the optional bank and balance constraints are in the schema, so no critical details are missing.

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?

The description mentions 'balance' but only echoes the parameter name; it does not explain units, currency, or the numeric constraints (0–10,000,000). The 'bank' parameter is left entirely to the schema description, and with 50% schema coverage, the description does not fully compensate for the missing balance parameter documentation.

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 uses a specific verb ('Estimate') and identifies the resource ('annual savings gap for a balance'), clearly conveying what the tool computes. It also references 'current Bank Gap Index assumptions,' differentiating this from sibling get_bank_gap_index, though it does not name the sibling explicitly.

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 guidance is given on when to use this tool versus alternatives like get_bank_gap_index or compare_switch_savings. The text only states what the tool does, leaving selection conditions entirely to inference.

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