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

Annotations already indicate readOnly, idempotent, and non-destructive, but the description adds substantial behavioral context: it is 'FREE, no API key,' examples are 'fixed handler-generated' and 'synthetic, not customer activity,' and it cannot spend credits. These details go well beyond the structured annotations.

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 sentences, no filler, with the most attention-grabbing facts ('FREE, no API key') front-loaded. Each sentence adds distinct value: pricing, purpose, and constraints.

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?

For a tool with one constrained enum parameter and rich annotations, the description covers the tool's purpose, input expectation, limitations, and synthetic nature of the output. No output schema exists, but the description clearly says it returns an input/output example, which is sufficient.

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?

With schema description coverage at 0%, the description compensates by clarifying that the sole parameter 'Accepts only a tool name' and is not for custom input. The enum in the schema provides the allowable tool names, and the description's framing tells the agent the parameter identifies which example to view.

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 action and resource: 'Read a fixed handler-generated input/output example for a listed non-network tool.' It also differentiates itself from execution tools by noting it 'cannot run custom input, access a wallet or spend credits,' making its purpose distinct from siblings like agent_utilities_prepare.

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 gives clear context: use this tool 'before deciding whether to pay' and for previewing examples. It also implies exclusions by stating it cannot run custom input or access a wallet, but it does not explicitly name alternative sibling tools or give a when-not-to-use condition beyond those constraints.

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