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

Adds significant behavioral context beyond annotations: specific data sources (World Bank, IMF, SEC), output types (exposure, efficiency scores, risk flags), and a mandatory async requirement to avoid a x402 timeout. This enriches the read-only/open-world/idempotent hints provided by annotations.

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?

Five sentences, each contributing distinct information (audience, analysis scope, inputs, outputs, data sources, async requirement). Well-structured and front-loaded with purpose. Slightly longer than strictly necessary but no filler.

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 complexity of cross-border tax analysis, the description covers purpose, inputs, outputs, data sources, and a critical async requirement. With an output schema present and strong annotations, this is complete enough for an agent to select and invoke 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 coverage is 100%, so baseline is 3. The description adds meaning for the async parameter by explaining it is REQUIRED to avoid timeout, and mentions acquirer/target jurisdictions, deal structure, and transaction value as inputs. It doesn't detail all params, but the async note goes beyond 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 states a specific verb ('analyzes tax efficiency') and resource ('mapping withholding tax rates, transfer pricing regulations, and permanent establishment risks across specified jurisdictions'). It clearly distinguishes from siblings by focusing on tax efficiency for cross-border M&A, and lists concrete outputs.

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?

Provides clear context ('For CFOs evaluating cross-border M&A deals') and describes inputs, but does not explicitly name alternatives or when-not-to-use. The async note also gives practical usage guidance. Lacks explicit exclusions or alternative tool mentions, which prevents a 5.

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