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

With no annotations, the description carries the full behavioral burden. It discloses that results are engagement-based and not a follower census, normally cost 3 credits, are not charged on empty results/failures, and support a free 24-hour cache hit via cache=true while defaulting to fresh data. The 'Costs 3 credits' phrasing is slightly oversimplified since videos=30/60 cost more, but the schema clarifies this and the overall disclosure is strong.

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?

Three sentences with no filler: the first states core purpose and methodology, the second covers pricing and failure billing, and the third explains cache behavior. Information is front-loaded and every sentence earns its place.

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?

The description covers purpose, sampling methodology, cost, failure billing, and caching, which are the key elements for selecting and invoking the tool correctly. A brief mention of the output structure would have been helpful given there is no output schema, but the first sentence and the countriesLimit schema description referencing audienceLocations provide enough high-level context.

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 all four parameters and the baseline is 3. The description adds little beyond what the schema already states about cache and cost; it actually provides less precise cost information than the videos parameter's description. No additional meaning is provided for url, videos, or countriesLimit.

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 clearly states the data domain: audience country and language mix for a TikTok creator, with an important scoping detail ('engagement sample, not a follower census'). It does not use an explicit verb like 'retrieves' and does not name sibling tools to differentiate from alternatives such as tiktok_profile_region or tiktok_channel_details, but the resource and resource type are unambiguous.

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 implies when to use this tool (when you need a TikTok creator's audience country/language mix) and gives practical guidance on cost, non-charging of empty results/failures, and the cache=true free hit. However, it does not explicitly compare to alternative TikTok endpoints or state when not to use this tool, leaving selection vs. siblings to inference.

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