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 that this returns suggestions (not full search results) for a partial keyword, which is useful context, but says nothing about suggestion ordering, regional/personalization effects, or how many results typical queries return. Adequate but shallow beyond annotations.

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?

A single twelve-word sentence with the key qualifier 'partial keyword' at the end and no filler. Nothing could be removed without losing meaning.

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?

An output schema exists and all parameters are documented, so return values need not be explained. The description is sufficient for correct invocation; the only meaningful gap is that it does not route the agent to or away from sibling search 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 coverage is 100%, with both 'keyword' and 'count' fully described including the 50 cap. The description reinforces the partial-text semantics of 'keyword' but adds nothing about the count parameter or edge cases such as short prefixes. Baseline 3 is correct when the schema carries the detail.

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 (Retrieve) and a precise resource (TikTok search typeahead suggestions), qualified by 'partial keyword' which conveys the autocomplete nature. It distinguishes itself implicitly from the actual search tool, though it never names tiktok_mobile_search to make the separation explicit.

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 a partial keyword' implies the autocomplete use case, so an agent can infer this is a pre-search expansion step. However, there is no explicit statement of when to use this versus tiktok_mobile_search or tiktok_mobile_search_hashtags, and no mention that results are suggestions rather than content to act on directly.

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