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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds value beyond that with 'cursor-paginated' and the 'top-level' scope restriction, signaling that replies are excluded and results are paged. It stops short of noting ordering or rate limits, so not a 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?

Two compact sentences: the purpose first, then the alternative-tool routing. No filler, no repetition of schema or annotation content, and the key scope constraint ('top-level') 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 two-parameter read tool with an output schema and read-only annotations, the definition covers purpose, scope, pagination, and sibling routing. Return formatting is handled by the output schema, so nothing an agent needs to invoke 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 both the cursor and aweme_id semantics (including the example id and 'pass the cursor from a previous response') are already documented. The description adds no syntax or format detail beyond the schema, which is the expected baseline here.

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 (Fetch), resource (comment records), scope (top-level, for a TikTok video), and even the pagination style. The 'top-level' qualifier distinguishes it from reply-fetching, and it names the sibling tiktok_post, so an agent can tell them apart without opening either schema.

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?

Explicitly routes the agent: 'Use tiktok_post for the video post's metadata or reply context.' This names the alternative tool and the two conditions (metadata, replies) that select it, leaving nothing to inference about when to prefer this one.

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