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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real behavioral context: it returns only accounts selected at connect time, the response carries default_account_id, and all_accessible widens the reach. That is meaningful beyond the structured 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?

Two tight sentences, front-loaded with the core behavior and then the parameter semantics. No filler or repetition.

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 annotations covering safety and an output schema covering return values, the description only needs to add scope and parameter meaning, which it does. Minor gap: no note on what happens when no account is connected or when the credential lacks TikTok access.

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 0% and the single parameter (all_accessible) is undocumented in the schema, so the description must carry it — and it does, explaining that all_accessible=true returns every account the credential can reach versus the default filtered set.

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+resource ('Lists the user's connected TikTok ad account(s)') and distinguishes itself from the many list_tiktok_* siblings by scoping to accounts. It does not explicitly name an alternative tool, but the resource is unambiguous.

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?

Usage is implied rather than stated: the default (only connect-time selected accounts) versus all_accessible=true is described, which hints at when to set the flag, but there is no explicit 'use this when' or exclusion guidance relative to siblings like list_tiktok_bc_advertisers or connect_tiktok_ads.

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