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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds only what rich=true returns, which is also in the schema. It omits that output is Google autosuggest behavior (live external data, no caching unless nocache) beyond what annotations state.

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 sentences, zero waste. The core purpose is front-loaded and the option guidance follows immediately.

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?

With 7 params all schema-documented, an output schema, and annotations covering safety, the description is nearly complete for the purpose. It could note count clamping or that it is a live external call, but for a suggest endpoint the current content 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?

Schema coverage is 100%, so the schema already documents q, lang, rich, count, source, country and nocache. The description restates source values and the rich flag but adds no format or semantics beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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: 'Returns Google autosuggest query completions for a prefix.' An agent knows exactly what it gets. It doesn't differentiate from the many sibling suggest tools (baidu_suggest, bing_suggest, etc.), so it stops 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?

Implies usage ('for a prefix') and gives conditionals for source and rich, but never says when to pick this tool over sibling suggest tools or when not to use it. Enough to act, not enough to route.

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