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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail about the output split (top vs. rising), but it does not mention rate limits or data freshness. With annotations present, this is adequate but not richer.

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 a single compact sentence that front-loads the core action and outcome, then adds usage context. Every phrase earns its place, with no redundancy or fluff.

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 no output schema and no parameter descriptions, the description carries more weight. It explains the output categories (top/rising) and the primary parameter (keyword), but leaves the optional geo parameter and the exact result format unspecified. For a low-complexity tool with annotations, this is adequate but not complete.

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%, so the description must compensate. It explicitly clarifies the required 'keyword' parameter (the term for which related queries are fetched), but it says nothing about the optional 'geo' parameter. This is partial compensation for the schema gap.

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 uses a specific verb ('获取'/'get') and a clear resource ('相关搜索词' for a keyword in Google Trends), and further specifies the two output categories (top and rising). This immediately conveys the tool's function and naturally distinguishes it from siblings like keyword_trend_curve or get_trending.

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 states a clear application context: '用于选题与 SEO/搜索流量' (for topic selection and SEO/search traffic). It does not explicitly name alternatives or provide exclusions, but it tells the agent when this tool is appropriate.

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