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

Adds substantial context beyond annotations: deterministic output, no logging, response fields, Arabic number–noun agreement, minor-unit handling, and CLDR currency naming. These details help the agent understand domain behavior beyond the safe-read annotation profile.

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 purpose is front-loaded, and the paragraph packs examples, language behavior, style behavior, and response details without obvious filler. Every sentence contributes actionable context.

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 output schema and rich annotations, the description supplies the remaining domain context: determinism, no logging, Arabic agreement rules, currency naming, and style semantics. An agent has enough information 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 schema already documents all parameters; the description still adds useful meaning through the amount example, the 56-language scope, and the effect of style='cheque'. It does not fully restate all parameter constraints, but it adds meaningful domain context.

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?

States a specific verb and resource: convert a currency amount to words, with concrete domains (cheques, invoices, contracts) and language scope. It is distinguishable from generic siblings like number_to_words by its currency-specific behavior, though it does not explicitly name the alternative.

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?

Gives clear use contexts ('for cheques, invoices and contracts') and explains that style='cheque' adds the customary wrapper. It lacks explicit when-not guidance or named alternatives, but the intended usage is clear.

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