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

With no annotations, the description carries the full behavioral burden. It discloses key computation rules (T+2/T+1 conventions, joint holiday calendars), which is useful, but it omits error handling, convention selection logic, and any edge-case behavior.

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, front-loaded sentence that efficiently covers purpose and key conventions without any wasted words.

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 low-complexity, two-parameter tool with no output schema, the description provides sufficient context for correct invocation. It explains the date calculation basis, though it could mention error cases or which convention applies to which pair.

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% for both parameters, and the description adds no meaning beyond what the schema already provides. A baseline score of 3 is appropriate when the schema fully documents the inputs.

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 returns the FX spot value date for a given currency pair and trade date, with specific conventions. It is more than a tautology and the domain is distinct from the generic calendar siblings, but it does not explicitly differentiate itself from alternatives like add_business_days.

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?

No guidance is given on when to use this tool versus the sibling calendar functions, nor are any exclusions or prerequisites mentioned. The domain-specific name implies usage, but the description provides no actual when-to-use instructions.

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