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

With empty annotations, the description carries full transparency burden. It discloses a confirmation step, currency conversion behavior, and geographic restriction. These are meaningful behavioral traits not inferable from the schema. It doesn't cover failure modes, but the disclosed details are substantial.

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 structure is clear with a lead statement, behavioral note, and parameter list. However, the opening sentence is duplicated exactly in the second paragraph, adding unnecessary repetition. Otherwise, every part serves a purpose and the @param block is well-organized.

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 description covers purpose, restrictions, parameter semantics, and a confirmation workflow. Since an output schema exists, the generic '@return: a json object' is acceptable. Minor gaps include error handling or post-execution effects, but the overall context is sufficient for a financial transaction tool.

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?

All five parameters are individually documented with added meaning beyond the schema. Notably, account_fk is clarified as a database ID (int) not an address, must not be 0, and is sourced from /wallet/accounts_list. Mobile is specified as the South Africa mobile number. This is critical given the schema has 0% description coverage.

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's function: 'Funds an account with an OTT Voucher.' This is a specific verb+resource combo that distinguishes it from sibling tools like fund_banks or fund_card_recharge. The repeated sentence reinforces the purpose without ambiguity.

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 concrete usage conditions: only available in South Africa, only redeemable against any currency account, and system performs currency conversion. It also instructs to confirm (yes/no) before executing. While it doesn't name alternative tools, these constraints effectively scope when to use this tool.

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