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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description does add genuinely useful context beyond that: pagination via cursor, the fact that it uses Kwai's public web API rather than scraping, and that repeated requests may re-purchase data. That value is undercut by self-contradictory pricing text ('at least 10 Nexscope credits' versus '1 credit per request'), which leaves the agent uncertain about actual cost.

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 first sentence is exemplary — front-loaded, specific, no waste. It is followed by a block of pasted marketing/pricing boilerplate that repeats itself, mixes supplier-unit language with credit language, and contains internally inconsistent numbers ('at least 10 credits' vs '1 credit per request'). That tail materially dilutes a description that could be two clean sentences.

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 simple read-only paginated list tool with no output schema, the description covers the essentials: what comes back, how to paginate, and that it hits the public API. Annotations carry the safety profile. The only gap is the muddled cost statement, which is more confusing than absent.

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 of the four parameters documented (url/handle alternates, count max 50, cursor from previous response). The description only restates the cursor continuity ('the next cursor when more results are available') and adds no format, precedence, or default guidance beyond the schema, so the baseline 3 applies.

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 opening sentence gives a specific verb and resource ('Fetches a paginated list of public Kwai posts for a user') and even enumerates the payload fields returned, which clearly separates it from the single-post sibling social_kwai_post. However, it never names or contrasts against social_kwai_profile or social_kwai_post explicitly, so sibling differentiation is left to inference.

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 phrase 'Get public posts from a Kwai handle or profile URL' implies the input requirement but gives no when-to-use guidance, no when-not-to-use conditions, and no reference to the obvious alternatives (social_kwai_post for a single post, social_kwai_profile for account metadata). The agent must decide purely from the name.

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