Top Up Potarix Credits

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

Description adds context beyond destructiveHint=true: it charges off-session and returns immediately on success. However, it does not mention failure scenarios (e.g., insufficient funds).

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?

Two succinct sentences with no extraneous information. Key points (buying, charging, alternative) are front-loaded and clearly separated.

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 single-parameter tool with annotations already indicating destructive nature, the description covers the core workflow, prerequisites, and behavior. No output schema is needed, and the description suffices.

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?

The input schema already covers the parameter tier_key with enum values and descriptions. The description adds no further parameter information beyond what the schema provides (100% 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 begins with 'Buy a credit pack', clearly specifying the verb 'buy' and the resource 'credit pack'. It distinguishes from sibling tools by referencing start_checkout as a prerequisite when no card is saved.

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 provides explicit guidance on when to use this tool (buying credits) and when to use an alternative (start_checkout if no card is saved), including exact tool name.

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