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

With no annotations provided, the description carries the full behavioral burden and does substantial work: it discloses the 2-credit cost, the 404-at-0-credits edge case for unresolvable videos, no-charge on empty/failed results, and the free 24h cache hit with default-fresh behavior. It stops short of covering auth needs or rate limits, but the pricing, failure, and caching semantics are unusually explicit for a description.

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?

Four short sentences front-load the core purpose and pack in output-shape, pricing, failure, and caching semantics without filler. There is minor pricing redundancy ('Costs 2 credits', 'never charged', 'free 24h cache hit'), but each mention adds a distinct nuance, so every clause 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 tool with no annotations and no output schema, the description covers pricing, failure modes, caching behavior, and key response fields, while leaving pagination mechanics to the well-documented schema. It is missing only minor context such as rate limits and authentication expectations, which are likely shared across the account-level sibling tools.

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 baseline is 3; the schema already documents url (with cross-platform warnings), cache, limit, and cursor/nextCursor pagination. The description adds only marginal value by tying cache=true to the free 24h cache hit, which mostly restates what the schema's cache parameter already explains.

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 states the resource ('TikTok comments') and hints at the output shape (authorName, stable authorId/authorSecUid, commentLanguage), making the tool's function unambiguous. It lacks an explicit verb like 'fetch' or 'list' and never names sibling tools such as tiktok_comment_replies, so sibling differentiation relies on inference from the platform and field details rather than explicit statement.

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 phrase 'for listening loops' implies a use case (tracking commenters over time via stable author IDs), and the cache/cost notes signal when the cheap path applies. However, there is no explicit when-to-use guidance, no exclusions, and no mention of alternatives like tiktok_comment_replies or youtube_comments, so an agent must infer when this tool is preferred over siblings.

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