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

No annotations are supplied, so the description carries the full burden. It does add genuinely useful context by stating that auth and charges are governed by the caller's OpenAny gateway credentials, which tells the agent this is a paid, credential-dependent call. It stops short of stating whether this specific call costs credits, what happens on auth failure, or what the response contains.

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, front-loaded, with no filler. The first sentence is a redundant restatement of the title, which is the only wasted line; the second 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?

For a 4-parameter paid search tool with no annotations and no output schema, the definition covers billing/auth source but omits what the results look like, whether a Douyin web cookie (an exposed parameter) is required for this endpoint, and any cost or rate-limit detail. Adequate but with clear gaps.

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 keyword, count, cursor and cookie are already documented in the schema (including pagination semantics for cursor). The description adds no meaning beyond that, so the baseline of 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 description repeats the title verbatim: 'Search videos (by title)', which does establish a specific verb and resource. However, in a namespace crowded with dozens of Douyin and generic video-search siblings (e.g. tikhub_post_api_v1_douyin_search_fetch_video_search_v1..v5), it never signals that this one targets the Douplus advertising platform and so is not clearly distinguishable from alternatives.

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?

There is no guidance on when to use this tool versus the many other video-search siblings, no prerequisites, and no exclusion criteria. The only contextual hint is the gateway billing sentence, which does not help an agent choose between tools.

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