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

With no annotations provided, the description carries the behavioral burden. It does disclose that missing inputs fall back to documented defaults and lists the calculation stages the tool will produce. It does not specify the return format, whether the operation is purely computational, or how results are structured, leaving some behavioral ambiguity.

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 description is compact, front-loads the action ('Run the Section 877A exit tax calculator'), and uses a clean list for the output stages. The 'calculator calculator' typo is a minor flaw but does not materially hurt clarity.

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 calculation tool with five fully documented optional parameters and no output schema, the description names the main computed outputs and the default-fallback behavior, which supports a basic invocation. It does not describe the output container, labeling, or return value shape, so an agent still has to infer part of the response contract.

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 input schema has 100% description coverage, documenting all five parameters with defaults, ranges, and descriptions. The description adds no new parameter semantics beyond noting that missing inputs fall back to documented defaults, which largely restates what the schema already expresses. The baseline of 3 applies.

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 clearly identifies the tool as 'Run the Section 877A exit tax calculator' and enumerates the specific computed outcomes: covered expatriate status, applicable test, exclusion applied, and gain subject to the exit tax. This separates it from the sibling describe/enquiry tools by making its calculation role explicit, though it does not name those alternatives.

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?

The description implies this tool is for running the exit tax calculation and that missing inputs will use defaults, which gives some sense of when to call it. However, it gives no explicit guidance about when not to use it or when to prefer siblings like calculator_describe or enquiry_describe.

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