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

Beyond the readOnlyHint and openWorldHint annotations, the description adds important behavioral context: results may take up to ~15 seconds, each successful call costs $0.002 USDC via x402 on Base, Solana, or Arc, and failed calls are not charged. This discloses latency, payment, and billing-failure behavior that an agent would otherwise not know.

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 front-loaded with purpose and scope, then efficiently covers licensing, latency, and pricing. Each sentence contributes distinct operational information, with no filler.

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 simple two-parameter schema, existing output schema, and read-only/open-world annotations, the description supplies the remaining operationally relevant details: content scope, licensing, latency, cost, and charge-failure policy. An agent has enough information to decide whether and how to call it.

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 input schema already has 100% description coverage for both parameters (q and limit), so the schema carries the main burden of parameter semantics. The description adds context about the result type and licensing but does not add query syntax or limit behavior beyond the 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?

The description states a specific verb and resource: Openverse openly licensed image search, scoped to Creative Commons and public domain images only. It also lists the returned fields and clarifies that each result carries its own license, which makes the tool easy to distinguish from generic web-search siblings.

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 use case clear through "openly licensed image search" and "Images only," so an agent can infer when it is appropriate. However, it does not explicitly name when not to use it or point to alternative image/search tools, leaving usage guidance implied rather than stated.

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