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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds substantive behavior beyond that: the result rolls forward over weekends and public holidays in both currencies' financial centres, which is exactly the context an agent needs to trust the output. Error handling for invalid tenors or pairs is not disclosed.

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 core purpose and trigger are front-loaded, and the length is reasonable for the amount of format detail conveyed. The format list and the examples ('3M' = 3 months, etc.) are partially redundant with each other, costing a little tightness.

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 two-parameter, read-only computation with no output schema, the description covers the purpose, the input format, the business-day adjustment logic and the downstream handoff. An agent has everything needed to invoke it 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 the baseline is 3, but the description goes further by enumerating valid tenor units (1D/1W/1M/1Y) and worked examples (3M, 6M, 1Y), clarifying the expected string format. The currencyPair parameter format is left largely to the schema's GBPUSD example.

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 and resource: converting a relative tenor into a valid business settlement date for a currency pair. It is clearly distinguishable from all siblings (none of which perform date resolution), and it names the downstream tool (price_guard) that consumes the result.

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?

Explicit trigger is given: 'Use this when a user says "3 months", "6 months"... instead of an exact date,' which also implies the when-not case. The handoff 'use the returned settlementDate as the exact date parameter for price_guard' adds routing value, but no sibling alternative for date resolution is named (there may be none).

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