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

Annotations declare destructiveHint=true, readOnlyHint=false and openWorldHint=true, but the description offers no behavioral context at all — nothing about credit consumption, the 5-minute cache that the schema mentions, rate limits, or why a search operation carries a destructive hint. With such a loaded annotation profile, the description should have carried more explanatory weight.

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?

A single compact sentence with the purpose front-loaded before the qualifying dimensions. No padding or repetition, though it is somewhat list-like in its enumeration of parameters rather than prioritizing the most important selection cues.

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 14-parameter tool with no output schema, the description is thin: it omits result format/pagination behavior and the cost/credit implications hinted at by the destructive annotation and cache parameter. It is adequate as a trigger statement but not complete enough to call this tool confidently.

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% with 14 fully documented parameters, so the schema does the heavy lifting and baseline 3 applies. The description only broadly gestures at 'region, language, location, safe filtering, time conditions' without adding syntax, format, or interaction detail (e.g., the uule/location mutual exclusion) beyond what the schema already states.

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 verb+resource combination ('通过 Google Videos 搜索视频结果') and enumerates the scoping dimensions it supports (region, language, location, safe filter, time). It is clearly distinguishable as a video-SERP tool, though it never contrasts itself with siblings such as bing_videos or youtube_video, so it falls short of full sibling differentiation.

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 gives trigger conditions ('当用户需要...时触发') and lists the situational dimensions, which is more than implied usage but stops short of explicit when-not guidance. No alternative tool is named for video searches (e.g., bing_videos for Bing, youtube_video for YouTube-native content), leaving the routing decision to inference.

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