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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: ~30 videos per page, empty list for accounts hiding likes, and a $0.006 per page billing rate — cost and edge-case behavior an agent would otherwise not know.

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 tight sentences: identical verb/resource scoping first, then identity constraint, then pagination, edge case, and cost. No sentence is redundant and the key constraint 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 read-only, no-output-schema endpoint, the description covers pagination yield, billing, an important empty-result edge case, and points to a sibling for the return shape. Nothing needed to call it correctly is missing.

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 all five parameters are already documented, including the exactly-one constraint and page sizing. The description adds only the 'about 30 per page' yield figure, 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 ('Get the videos a TikTok user has liked') and enumerates the three accepted identifiers. It also explicitly distinguishes itself from tiktok_user_videos by noting it returns the same video fields, so an agent can tell the two apart without opening 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 the concrete invocation constraint 'provide exactly one' of username/user_id/url, which is essential guidance. It lacks explicit when-not guidance (e.g., when to prefer tiktok_user_videos or how this differs for analytics use), but the operating context is clear.

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