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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: results are newest-first, identity_type can be left empty and is auto-resolved, and BC_AUTH_TT Business Center id resolution is automatic. It stops short of describing pagination or result caps beyond the schema's limit default, hence a 4.

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?

Front-loaded with the core purpose and the item_id -> tiktok_item_id handoff, then layered account-type detail. Parenthetical digressions add density rather than waste, though the paragraph is longer than strictly necessary.

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, so return-value explanation is not required, and the description still names the key return fields. Combined with the workflow routing and account-type handling, an agent has everything needed to select and invoke this tool correctly.

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%, so the description must compensate, and it does for identity_id (source), identity_type (TT_USER vs BC_AUTH_TT, leave-empty behavior), and identity_bc_id (pass only when multiple Business Centers). advertiser_id and limit are left undocumented, so it is strong but not complete.

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+'ORGANIC TIKTOK POSTS of a connected TikTok account' and ties it to the Spark Ads use case. It also distinguishes itself from the adjacent create_tiktok_ad (downstream consumer) and list_tiktok_identities (upstream source of identity_id), so an agent can place it in the workflow without opening other schemas.

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?

Explicit about when to use it ('this is how you promote an existing post without re-uploading'), where identity_id comes from, what to do with the returned item_id, and which account types are eligible (CUSTOMIZED_USER has no organic posts). It even states the condition that selects the identity_bc_id parameter.

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