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

Annotations declare this a non-readonly, destructive, non-idempotent, open-world operation, and the description does confirm it submits an async Builder task. But it omits anything an agent needs behaviorally: that the call returns a task to be polled (via scraper_task_status/scraper_task_result), that repeated calls with the same URL may duplicate tasks despite non-idempotency, and any auth or rate-limit expectations.

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 substantive content is a single well-formed sentence, but the leading trigger-word enumeration ('Reddit 帖子评论、Reddit 评论、Reddit post comments、Reddit 回复信息') is redundant padding that repeats the same concept four times before the actual purpose statement.

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?

This is a task-submission tool with no output schema, so the description must carry the full lifecycle burden. It never explains that a task is created asynchronously or points to the sibling tools (scraper_task_status, scraper_task_result, scraper_task_list) needed to retrieve results, leaving a major gap for a 4-parameter write tool.

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 schema already documents url, days_back, file_name, and comment_limit. The description adds only the fixed collector identifier (reddit_comment_by-url), which is marginal value over the schema and does not clarify the defaults or format constraints further.

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 second sentence states a specific verb+resource: it submits a Reddit post comment collection Builder task with a fixed collector id (reddit_comment_by-url). That distinguishes it from reddit_posts (which would fetch posts, not comments). The first sentence, however, is a trigger-keyword list rather than purpose prose, which dilutes clarity.

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 lists triggering keyword combinations ('Reddit 帖子评论' + collect/scrape/crawl/fetch/extract), which implies the usage context. But it never says when to prefer this over siblings like reddit_posts or when not to use it, nor mentions the one-URL-per-call constraint, so guidance is only implied.

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