prufa_buy_credits

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

With no annotations, description discloses mutating and idempotent nature, and that payment is handled via external URL. Lacks rate limits or auth details but covers key behaviors.

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 concise sentences plus key tags; no wasted words. Front-loaded with essential purpose and outcome.

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?

No output schema but description states return value (checkout URL). All params documented. Sibling tools indicate this is a distinct purchase action; sufficient for selection.

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 already covers all param descriptions (100%), but description adds context about idempotency key and checkout URL, enhancing understanding beyond 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?

Verb 'Buy' specifies action, resource 'prepaid credit pack' is precise, and description distinguishes from subscription changes (contrasts with prufa_upgrade_plan).

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?

Explicitly states use case: 'when workspace is low on credits but you don't want to change the plan', providing clear when-to-use and when-not-to-use guidance.

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