GoAI Moat Cross-Border Tax Compliance

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

With no annotations provided, the description carries the full burden. It clearly states what the tool returns (frequency, deadlines, retention, risk), which implies a read-only informational behavior, but it does not explicitly declare its non-mutating nature or any limitations. No contradictions are present, and the description is adequate for this straightforward reference tool.

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 and well-organized: a single-sentence purpose, a structured parameter list, and a return summary. Every element earns its place, with no filler or redundancy. The key information is front-loaded.

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 simple one-parameter tool with an output schema, the description covers the essential inputs and high-level outputs. It does not explain exact return formats, but the output schema likely handles that. It could explicitly state that the tool is a read-only reference, but this is a minor gap given the tool's simplicity.

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%, so the description must compensate. It does so by explicitly enumerating the allowed values for 'market' (UK, EU, US) and explaining it is the target market. This adds crucial meaning beyond the bare string type in the schema.

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 states the tool provides a filing obligation calendar covering frequency, deadline cadence, record retention, and late risk for UK/EU/US. It distinguishes itself from siblings (us_sales_tax_nexus and vat_registration_guide) by focusing on ongoing filing obligations rather than nexus or registration, though it does not explicitly name 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?

The description implies when to use the tool via the 'market' parameter and the explicit return topics, but it does not explicitly compare with siblings or state when not to use it. The intended scenario is inferable, but there is no explicit routing or exclusion guidance.

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

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

No annotations are provided, so the description carries the full disclosure burden. It does describe the main processing logic (economic/physical nexus), the return components, and the fallback behavior when states_sales is missing. However, it omits important behavioral context such as legal threshold assumptions, whether the determination is advisory, and data freshness or accuracy limitations.

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 well-structured with a clear summary, parameter list, and return summary. Every sentence provides useful information, and the example is concise yet illustrative. It avoids unnecessary repetition despite the title already naming the domain.

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 two optional parameters, zero required parameters, and the presence of an output schema, the description covers the essential inputs, fallback behavior, and return contents. It lacks explicit legal caveats and sibling differentiation, which prevents a perfect score, but it is sufficient for an agent to invoke the tool correctly.

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%, but the description fully compensates by explaining both parameters in detail. It defines states_sales with state-code keys, sales amounts, transaction counts, a concrete example, and the default behavior; it also defines has_physical_presence with examples such as warehouses, offices, employees, and return points.

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 states that the tool determines US sales tax nexus by evaluating economic nexus and physical nexus, producing a list of states requiring registration plus marketplace facilitator collection tips. This is a specific verb+resource, though it does not explicitly differentiate itself from sibling tools like tax_filing_planner or vat_registration_guide.

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 guidance about when to use this tool versus the sibling tools, and no exclusions or prerequisites are stated. The only usage-related hint is the default framework explanation returned when states_sales is omitted, which does not help an agent choose between alternatives.

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

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

With no annotations provided, the description carries the behavioral burden. It defines input semantics and enumerates the returned components: registration need, thresholds, OSS/IOSS applicability, marketplace-facilitator notes, voluntary-registration advice, and late-risk. It does not discuss limitations or side effects, but the 'decision tree/guide' framing makes the advisory, non-destructive nature clear.

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 front-loads the purpose, then uses a compact bullet-style parameter list and a return-value list. Every sentence contributes useful information, with no filler or repetition.

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?

Combined with an output schema, the description is nearly complete: all inputs are explained and the output categories are listed. The only notable gap is the absence of guidance for choosing among sibling tools, which matters because tax_filing_planner covers an adjacent tax task.

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%, so the parameter section is essential and delivers: it defines all four parameters, including accepted country values, the established/non-established seller_type values, currency conventions, and an example for has_local_stock. This adds substantial meaning beyond the bare schema.

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 opens with a specific object ('VAT registration decision tree') and spells out what it determines: registration need, thresholds, OSS/IOSS applicability, and voluntary-registration advice. The UK/EU scope plus the 'registration' focus clearly distinguishes it from siblings like us_sales_tax_nexus and tax_filing_planner.

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 UK/EU VAT-registration scope implies the use case, but the description does not explicitly mention sibling tools or state when to choose this tool instead of tax_filing_planner or us_sales_tax_nexus. An agent has to infer that this is the registration-decision tool rather than the filing-planning tool.

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