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

With no annotations, the description carries the behavioral disclosure burden. It says the tool evaluates physical presence days, exclusion limits, and domicile audit risks, but it does not state whether the tool returns a calculation, a risk score, a flag, or a report, nor does it mention any caveats.

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 a single dense sentence with no filler; every clause contributes a distinct element: physical presence test, exclusion limit, and state audit risk. It is front-loaded with the core topic and remains highly scannable.

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?

The description covers the domain, key thresholds, and relevant states, and the schema documents all parameters. However, with no output schema and no annotations, the absence of any statement about what the tool returns or how results are presented leaves a meaningful gap for an agent relying on the description alone.

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%, so the baseline is 3. The description adds meaningful semantic context beyond the schema by linking the 330-day threshold to daysOutsideUSInRollingPeriod, the $130k limit to foreignEarnedIncome, and CA/NY/VA/SC to stateDomicile.

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 ('Track'), a specific IRS form (2555), and concrete thresholds (330 days, $130k, high-risk states), making the tool's purpose unmistakable. It clearly distinguishes this from sibling tax tools by focusing on FEIE physical presence and domicile audit risk.

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 establishes clear context: use this for IRS Form 2555 FEIE tracking, physical presence testing, and state domicile audit risk. It does not explicitly name alternatives or say when not to use this tool, so it stops short of full guidance.

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