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

Annotations are present (readOnlyHint: false, openWorldHint: true, destructiveHint: false), but the description adds useful context like 'free, no payment' and 'live prices', implying a network read operation. However, it does not explicitly state what side effects (if any) exist, though listing is inherently non-destructive.

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 a single, concise sentence that front-loads the core action ('List ALL') and includes necessary details without fluff. Every word earns its place.

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 (0 params, output schema present), the description provides sufficient context: what is listed, scope, price info, example URLs, and cost. The output schema covers return structure, so the description is complete.

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 tool has zero parameters, so the description need not explain parameter meaning. It does add value by describing the output content (live prices, example URLs), which is helpful despite no params.

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 'List ALL Reelfy paid endpoints' with a specific verb and resource, and adds that it provides 'live prices and example URLs'. It is easily distinguished from sibling tools like call_endpoint or web_search.

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 implies usage (you can see all paid endpoints and prices) but does not explicitly state when to use this over alternatives such as call_endpoint. No direct 'use this when...' or 'instead of...' guidance is provided.

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