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

Annotations already declare readOnlyHint, openWorldHint, destructiveHint=false, and idempotentHint=false. The description adds meaningful behavior beyond that: it explains the allowlist constraint and the no-network fallback that returns a truthful zero-result response when runtime context is missing.

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?

Two tightly written sentences, with the core scope and runtime condition front-loaded. No sentence is wasted.

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?

The output schema and annotations reduce what the description must carry, and the description covers the important runtime fallback behavior. It remains incomplete for a three-parameter search tool because query, limit, and domains are undocumented in both the schema and the description.

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 0% for three parameters (query, limit, domains). The description does not explain what the query string does, how limit is applied, or how the domains array interacts with the approved-domain allowlist, leaving parameter semantics almost entirely undocumented.

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 gives a specific verb ('Searches') and resource scope ('approved owned or official public domains'), which distinguishes it from first-party search siblings. It does not explicitly name alternatives like search_first_party_context, so it falls short of a 5.

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?

It provides a runtime condition: use only when request-scoped external-search support is available, otherwise a zero-result response is returned. However, it gives no guidance on when to prefer this over sibling search tools such as search_first_party_context.

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