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

With empty annotations, the description carries the full burden but is ambiguous about actual behavior: it says 'Funds an account' yet also 'Returns bank details' without clarifying whether this tool initiates a payment or only provides instructions. It also omits side effects, reversibility, or what happens on failure, leaving significant uncertainty.

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 redundant, repeating 'Funds an account with a PayShap payment' twice. The first sentence is a run-on with a comma splice, and the @param section could be integrated more cleanly. Each sentence does not earn its place, reducing overall clarity.

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?

While an output schema exists, the description still lacks essential context: it does not explain the payment flow, whether this is a deposit instruction or an actual transfer, prerequisites beyond ZAR/South Africa, or error handling. The ambiguity between 'funds' and 'returns bank details' leaves the tool under-specified for practical use.

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 0%, but the description compensates fully with detailed @param lines. It explains the source of api_key, token, and importantly clarifies that account_fk is a database ID (int), not an account address, and may not be 0. This adds significant meaning beyond the raw schema.

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 purpose: 'Funds an account with a PayShap payment' and adds 'Returns bank details for a PayShap payment.' The resource (PayShap) is specific, distinguishing it from siblings like fund_payat and fund_ott, though the verb is slightly ambiguous about whether it executes a payment or merely returns instructions.

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 gives clear contextual constraints: 'Only available in South Africa and can only be redeemed against a ZAR currency account.' This tells an agent when to consider using this tool (South African ZAR funding) and implicitly when not to, but it does not name alternative tools or provide explicit when-not guidance.

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