TikTok Post

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

Annotations already declare readOnlyHint=true and openWorldHint=true, yet the description adds genuinely useful context: the response is 'raw HTML, often several hundred KB' (a payload-size warning) and that xhr swaps the return shape entirely. It does not cover auth, rate limits, or failure behavior, so it is 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 sentences plus a docs link, front-loaded with the core action and return type, with zero filler. The long URL is the only mildly wasteful element.

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 carries the return-value burden and does so for both modes (raw HTML vs XHR JSON list). Both parameters are fully documented in the schema, so the only remaining gap is operational detail like auth or rate limits.

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 100%, so baseline is 3; however the description adds meaning the schema does not carry plainly, namely that xhr yields 'a JSON list of the page's XHR/fetch requests instead of the HTML.' That clarifies the actual consequence of the flag rather than restating its type.

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 a specific verb and resource ('Fetch a TikTok video post by URL') and names the backing API target, so the agent knows exactly what the tool returns. It does not explicitly distinguish itself from scrape_as_markdown, which could also fetch an arbitrary URL, so it stops short of full sibling differentiation.

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?

'Use it to analyse a specific TikTok video' gives a usage context and the xhr sentence implies a second mode, but there is no guidance on when to prefer scrape_as_markdown or tiktok_shop_url instead, nor any exclusions or prerequisites.

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