Post a banner with credits

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

With no annotations provided, the description carries the full burden. It explains the credits cost, membership requirement, and error condition for free accounts. However, it does not detail side effects such as whether the banner becomes publicly visible immediately or if the action is reversible, leaving slight ambiguity.

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 concise and clear, with two sentences that front-load the primary action and then provide essential constraints. Every sentence adds necessary information without 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?

Given the tool's simplicity, the description covers the essential context: prerequisites (paid membership, credits), the action, and the error condition for ineligible users. It does not include an output schema, but that is not required for the tool's purpose. Minor missing details like confirmation of success are acceptable for this scope.

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 schema already describes both parameters, but the description adds valuable context: days are limited to 1-2 for paid members and credits are charged per day. This enriches the meaning of the parameters, though it does not cover every possible edge case (e.g., behavior when days exceed the limit).

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 action (posts an existing banner into rotation), the resource involved (banner), and the additional context of credits and membership. It implicitly distinguishes from sibling tools like create_banner by focusing on posting an existing banner.

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 explicitly specifies when the tool should be used (paid members with credits) and provides a clear condition for non-use (free accounts will get an error). It also mentions the required membership tiers, giving concrete guidance.

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