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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the description. The description adds the FY2027-schedule scoping and the existence of exception handling, but says nothing about how the fee is computed (e.g. percentage of the guaranteed portion) or that defaults are applied silently for omitted parameters.

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 compact sentence with the key qualifiers (fee type, program scope, schedule year) front-loaded and no filler. It is a noun phrase rather than a full statement of action, but nothing is wasted.

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?

All four parameters are covered by the schema and the tool is read-only, so little behavioral disclosure is needed. However, with no output schema, the description never indicates what is returned (a dollar fee amount, a rate, a breakdown), leaving a real gap for a calculator tool.

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 100% and every parameter, including the two enums, is documented inline, so the baseline of 3 applies. The description contributes only the schedule year and the vague 'with exceptions', which does not explain what each exception enum value changes about the result.

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 the specific resource (SBA upfront guaranty fee) and constrains it to the FY2027 schedule for Express or standard 7(a) loans, which matches the program enum in the schema. It does not explicitly contrast itself with siblings such as estimate_payment or get_max_rates_today, so the agent must infer the boundary itself.

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 statement of when to use this tool versus the other estimators, nor any prerequisite or exclusion guidance. The phrase 'with exceptions' hints that an exception path exists but does not tell the agent when to reach for it.

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