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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the read-only, network-facing profile is covered. The description adds a concrete cost signal ('1 credit'), which is valuable context not in the structured fields, but it says nothing about pagination via cursor or how many results a page returns.

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 dense sentence plus a short credit note. The two operating modes are front-loaded and every clause carries information; nothing is padded.

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 read-only scraping tool with no output schema and annotations covering the safety profile, the description does enough to route the call correctly but leaves pagination behavior (cursor) and result shape unaddressed, which matters for a tool that caps count at 50.

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 60%, and the description does add real value by explaining the conditional relationship between url, video_id and comment_id (which parameters apply to which mode). It leaves 'cursor' and 'count' completely unexplained in both schema and description, so half the pagination/limit semantics remain opaque.

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 the resource (comments) and the two modes it supports: top-level comments on a video, or replies to a single comment. It distinguishes itself from generic siblings like tiktokVideo and tiktokUser, though the phrasing 'Comments on a TikTok video' reads like a noun-as-verb and takes a moment to parse.

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?

Usage is implied through the parameter combinations ('url' for comments, 'comment_id plus the video url or video_id' for replies), which is genuinely useful routing information. However, it never states when an agent should pick this over a sibling tool, nor any preconditions.

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