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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the pagination behavior, but that is largely restated by the page_token schema field, and no other behavioral context (rate limits, ordering) is added.

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 front-loaded sentence that identifies the action and resource immediately, followed by the routing clause. The trailing semicolon clause is dense but each part carries useful information.

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?

An output schema exists, so return values need not be explained. The description covers pagination and ID sourcing for a moderate three-parameter read tool; only the reply ordering or depth semantics are left implicit.

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 each parameter already documented in detail, so the baseline is 3. The description reinforces where comment_id and video_id originate but adds no syntax or format meaning beyond the schema.

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 (读取/read), resource (完整回复列表/full reply list), and scope (按视频 ID和一级评论 ID), and explicitly names the sibling it is the alternate entry point to (haokan_get_comment_replies_by_url). An agent can distinguish this from by_url without opening either schema.

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 routes the agent: comment_id comes from the video comment list, and the alternative entry point is named as haokan_get_comment_replies_by_url. It stops short of stating the condition that selects one over the other beyond ID availability.

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