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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the stay-safe burden is lifted. The description adds the pagination detail ('use cursor when paginated') and the region-scoped behavior, which is useful. However, it does not disclose what shape the returned list takes or how pagination is surfaced, so the behavioral disclosure beyond the annotations is thin and earns a 3.

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?

Two short sentences, with the core purpose front-loaded. The second sentence ('Returns a list') is slightly redundant given 'List' already appears in the verb, but it is brief and the pagination note is valuable. No wasted elaboration or filler.

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 10-parameter tool with no output schema, the description is adequate but leaves gaps. It gives no shape of the returned items, no clarification of the redundant pagination parameters, and no note about whether region affects result count or ordering. The presence of schema-level descriptions for all parameters compensates somewhat, but the pagination mechanics are hinted rather than explained, so a 3 is appropriate.

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 100%, so the baseline is 3 even with no descriptor-level parameter explanation. The description contributes only the pagination cue ('use cursor'), but it never says which of the overlapping pagination parameters (pageSize, limit, offset, maxResults, max_results) functions as the cursor. The description adds marginal value without fully compensating for the confusing parameter family.

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 uses a specific verb ('List') plus a concrete resource ('currently trending TikTok posts for a region'). This clearly distinguishes it from search-based siblings like tiktok_search_top_list and tiktok_search_videos_list, and from other platforms' trending tools. It loses the fifth point because it doesn't explicitly name which sibling it is not, so an agent must rely on slight contextual differences to route correctly.

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 description provides no guidance on when to choose this tool over alternatives. With nearly a dozen TikTok sibling tools (tiktok_search_top_list, tiktok_collection_videos_list, tiktok_music_videos_list, tiktok_shop_products_list, etc.), there is no explicit direction about which scenario maps to this tool. The only usage hint is 'for a region', which is implicit at best and not framed as a decision rule.

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