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

No annotations are supplied, so the description carries the full disclosure burden; 'List' weakly implies a read-only operation but nothing confirms it. Nothing is said about result volume, ordering, pagination, or what 'open' means operationally. Worse, 'credit_kind is live or test' describes an enum that no parameter exposes, which is misleading rather than informative.

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?

Three short sentences, front-loaded with the core action, so it is not bloated. But two of the three sentences are contextless fragments ('The expected answer is not included', 'credit_kind is live or test') whose referents are never established, so brevity comes at the cost of 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?

With no annotations, no output schema, and no parameters, the description must explain the return shape and the calling workflow on its own, and it does neither. It never says what fields a listed prompt contains, whether ids are returned for use with submit_answer, or how many results to expect. The note that expected answers are withheld is the one genuinely useful disclosure.

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 declares zero parameters, which would normally warrant the baseline score of 4 since there is nothing to document. However, the description references 'credit_kind' with values live/test despite no such parameter existing, creating a phantom argument the agent may try to pass. That actively misleads rather than adding meaning.

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 verb+resource pair 'List open prompts' is identifiable, but 'prompts' and especially 'open' are never defined, so an agent cannot tell what state distinguishes an open prompt from a closed one. The trailing fragment 'credit_kind is live or test' introduces a concept with no clear relation to the stated purpose.

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?

There is no statement of when to call this versus siblings such as submit_answer or get_balance, nor any prerequisite or follow-up step. The one implicit hint is that expected answers are withheld, which suggests 'fetch then answer', but the agent must infer the workflow entirely.

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