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

With no annotations, the description carries the full burden and excels. It discloses read-only behavior, exclusions for expired/revoked/unverified posts, pagination termination conditions, short-lived receipt semantics, and the prohibition on reusing receipts across advertisers or OAuth routes.

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?

Every sentence is dense and purposeful, with the core purpose front-loaded and details ordered logically: item contents, usage instruction, exclusions, pagination, and receipt caveats. Despite its length, there is no fluff 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?

Given no output schema and no annotations, the description is remarkably complete. It specifies returned item fields, eligibility filtering, ineligible_reasons accounting, pagination completion criteria, required input provenance, and downstream integration with campaigns_quick_create 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 description coverage is 0%, so the description must compensate, and it does. It explains advertiser_id's source, limit's range (1..50), search's length limit (200 characters), and cursor's nature as an opaque next_cursor from the previous page. All four parameters receive meaningful semantic context beyond the schema.

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 opens with a specific verb and resource: 'List reusable Spark posts already authorized for one exact TikTok advertiser.' It clearly distinguishes this from sibling tools like spark_ads_authorize_codes by emphasizing listing already-authorized posts rather than authorizing new codes.

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 description gives strong context: advertiser_id must come from assets_list_ad_accounts, results feed into campaigns_quick_create, and the tool is read-only and does not authorize new codes. It stops short of explicitly naming alternative tools for authorization, though the exclusion is implied clearly enough.

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