Google AI Overview

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

Annotations already declare readOnlyHint and openWorldHint, lowering the bar. The description adds useful behavioral context beyond annotations: the response includes a synthesized answer with citations plus organic results, and organic results still come back even when no overview is generated.

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 with zero filler. The core value proposition and fallback behavior are front-loaded, and the use-case guidance is compressed into a single clear clause at the end.

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 read-only search tool with no output schema, the description covers the main output, the fallback behavior, and the decision rule for selecting it. Parameter semantics are fully handled by the schema, so nothing critical is missing.

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?

Schema description coverage is 100%, so the baseline is 3. The description does not add parameter-specific detail beyond the schema, but none is strictly needed because every parameter already has a thorough description.

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?

States a specific verb and resource: 'Search Google and get its AI Overview' with citations, alongside organic results. The description clearly differentiates this from the sibling by emphasizing the synthesized AI Overview rather than just a list of links.

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?

'Use when a summarised answer is more useful than a list of links' gives an explicit when-to-use rule with an implied alternative. It also covers the fallback case where Google renders no AI Overview but organic results still return, making the tool's scope clear.

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