get_v1_user_following_by_username

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

Annotations already declare readOnly/openWorld/non-destructive, so safety is covered; the description adds real behavioral context beyond them — that each call is a live billed TikTok request and that pagination is one page per call with next_page_id chaining. It stops short of describing the response payload shape (per-account fields), which is the only notable gap.

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?

Front-loads purpose then routing then pagination mechanics, with essentially no filler; the trailing '(GET /v1/user/following/by/username)' is mild redundancy against the tool name but harmless. Dense but every clause carries information.

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?

With no output schema, the description correctly carries the pagination contract and the next_page_id handoff, which is the main thing an agent needs to iterate pages. It is complete enough to call correctly, though it never hints at what fields come back per followed account.

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 only 33% (count and username undocumented in-schema), and the description compensates: it defines count as page size with default 30 and explains the page_id/next_page_id continuation contract. Username's format constraints (2-24 chars) are left to the schema only, keeping this below a 5.

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 ('List accounts a TikTok user follows by username') plus the paging granularity ('one page per call'). It explicitly names the sibling tools it is not (secUid variant, followers variant), so an agent can disambiguate without reading schemas.

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?

Gives an explicit selection rule: use this when you have a handle, use get_v1_user_following_by_secUid when you have the secUid, and get_v1_user_followers_by_username for followers. When-to-use and alternatives are both covered with no inference required.

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