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

The description discloses important behavioral traits beyond annotations: this is a TEST-mode operation, returns only credits_pending, credits remain non-spendable until confirm_credits succeeds, and a caller key is required. This is valuable context that annotations alone do not provide.

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 tightly packed sentences deliver the core purpose, the critical pending-state caveat, and the auth requirement. No filler or redundancy.

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?

With one required parameter, clear behavioral caveats, and no output schema, the description covers everything an agent needs to invoke it correctly: what it does, what it returns, what it does not do, and what credential is needed.

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% and the only parameter, pack_id, is already described as coming from list_credit_packs. The tool description adds little beyond 'for a pack,' so it does not meaningfully enhance the parameter semantics.

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 states a specific verb and resource: creates a Stripe TEST PaymentIntent for a credit pack via POST /credits/checkout. It clearly differentiates itself from confirm_credits by explaining this is intent-only and does not grant spendable credits.

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 makes the usage context clear: call this to initiate a checkout intent, not to actually grant credits. It names confirm_credits as the follow-up step, effectively routing the agent appropriately, though it could be even more explicit about when to prefer alternatives.

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