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

With no annotations provided, the description carries the full transparency burden, and it does meaningful work: it discloses the 2-credit cost, states that empty results and failures are never charged, and explains the cache behavior with a default of fresh results. This is strong behavioral coverage for a paid search tool, though it omits any note on rate limits or auth.

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 tightly written sentences deliver purpose, result contents, pricing, failure policy, and cache guidance with zero filler. The most important identification information is front-loaded.

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 4-parameter tool with no annotations and no output schema, the description covers the essential selection and invocation facts: what the tool returns, its cost, its failure-charge policy, and a cost-saving cache option. It does not fully describe the response structure, but it names the key output fields, which is sufficient given the schema handles parameter details.

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?

The input schema already documents all four parameters with 100% description coverage, so the baseline is 3. The tool description reinforces the cache behavior but does not add meaning beyond what the schema provides for q, limit, or region.

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 opens with 'TikTok Shop keyword search' and names the concrete result fields (priced products, sold, rating/reviews, typed discount, seller id), so the operation and output domain are clear. It does not explicitly name sibling tools it should be distinguished from, but the keyword-search framing already separates it from detail/review/showcase tools.

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 keyword-search intent plus the cache guidance ('Pass cache=true for a free 24h cache hit') provides useful invocation context and implies when to use it. However, it never explains when to choose this tool over siblings like tiktok_shop_products or tiktok_shop_product_details, so the when/where-not guidance remains implicit.

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