threads_publish_carousel

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

Beyond the annotations it discloses the required scope (threads_content_publish), the two-phase child/parent upload model, minimum ~60s processing time, that URLs and caption are transmitted unchanged, and that the result is non-idempotent with explicit duplicate-avoidance guidance after ambiguous failures. This is materially more than readOnlyHint/idempotentHint provide.

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 action and constraints, then prerequisites, then failure recovery. Every sentence carries operational weight, though 'This action is not idempotent' restates idempotentHint=false and the timeout sentence partially overlaps it.

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?

For a mutating, non-idempotent publish tool with 3 parameters, the definition covers authorization scope, input validation, latency, return value, and failure recovery. The output schema handles the return shape, so nothing an agent needs before calling is missing.

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 largely does: it explains image_url must be publicly reachable HTTP(S), alt_text caps at 1000 characters, and text is a single optional caption passed through verbatim. Only account_id is left unexplained, and the image ordering semantics (user-approved order maps to array order) are implied rather than stated.

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 and resource with hard constraints: 'Publish 2 to 20 images ... with one optional caption.' The 2-20 range implicitly distinguishes it from threads_publish_image (single image) and the carousel children/parent mechanics make the multi-image scope 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?

Gives an explicit precondition ('Use only after explicit approval of the account, images, order and caption'), names an exclusion set (videos, local files), and routes the agent to threads_list_posts after a timeout or unknown outcome. That is when-to-use, when-not-to-use, and an alternative, all present.

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