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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower, and the description adds genuinely new operational context: a cost of 1 credit and a one-profile-per-call scope. It stops short of describing failure behavior for unknown users or any rate limiting, which keeps it out of the top band.

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 short sentences with zero filler: the return contents are front-loaded and the cost/scope constraint follows. Every clause carries information an agent would otherwise have to guess.

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 usefully compensates by listing what comes back, and it discloses the credit cost. The remaining gap is that it does not mention the anyOf identifier requirement (uniqueId or secUid) or what happens when a profile is not found, though the schema enforces the identifier constraint itself.

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% and both parameters (secUid, uniqueId) are documented in the schema itself, including the 'no @' formatting and reuse-from-previous-call hint. The description adds no parameter-level meaning, so the baseline of 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?

Specific verb ('Get') plus a precisely scoped resource ('a TikTok creator's public profile'), followed by an enumeration of the returned fields (followers, following, likes, bio, avatar, verified). This clearly separates it from tiktok_search, tiktok_videos, and the x_profile sibling, which covers a different platform.

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?

'One call returns one profile' implies a single-entity lookup and implicitly warns against expecting bulk results, but there is no explicit when-to-use or when-not-to-use statement, and no routing to siblings such as tiktok_search for discovery. Usage is inferable rather than stated.

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