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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), so the description is not obligated to restate that. It adds genuine non-schema context: the credit cost of 20 points per call and a preview of the returned metric set. It stops short of describing failure modes for private/deleted accounts, which holds it below 5.

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 English sentence is well front-loaded and information-dense, but the Korean sentence is a near-complete duplicate rather than a distinct constraint, so half the body repeats without adding new semantics. The cost tag is compact and useful, keeping the overall structure acceptable.

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?

This is a simple two-parameter read tool with fully documented inputs; the description compensates for the absent output schema by listing the returned fields (followers, likes, video count, bio, recent popular videos). An agent has enough to invoke and interpret it, though account-state edge cases are unaddressed.

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%, and the schema already documents both url (with a format example) and username (with the '@ optional, either/or requirement). The description adds no parameter-level meaning 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?

States a specific verb and resource ('TikTok public profile') and enumerates exactly what is returned: followers, likes, videos count, bio, and recent popular videos with view and engagement counts. It is unmistakable against the sibling instagram_profile or crawl_youtube because the platform is named explicitly.

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 word 'public' implicitly scopes usage to public accounts, and the cost tag hints at a quota consideration, but there is no explicit when-to-use, when-not-to-use, or pointer to the sibling instagram_profile for other platforms. Usage must be inferred from the name and the public/private qualifier.

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