currency_format

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds the 'or other locale' claim but provides no mechanism to select a locale, which is slightly ambiguous. No contradiction with annotations, but the behavioral disclosure beyond annotations is minimal.

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 conveys the core purpose without any extraneous words. It is appropriately concise.

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 tool is simple, but the description lacks detail on output format specifics (e.g., rounding, grouping) and does not clarify how the 'other locale' is specified, especially since there is no locale parameter. Without an output schema, more behavioral detail would be beneficial, though the basic function is clear.

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%: both 'amount' and 'decimals' have descriptions. The description does not add any information beyond the schema, so the baseline of 3 applies.

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 'Format a number as USD currency string (or other locale)' clearly states a specific verb (format) and resource (number to currency string). It differentiates from sibling financial calculation tools like gross_margin and loan_amortization, making its purpose unmistakable.

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 the tool is used when a number needs to be formatted as currency, which is clear context. However, it does not explicitly state when not to use it or name alternatives, though the sibling tools are all calculations, so the distinction is implicit.

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