Publish an original post (optionally a self-thread), with media

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

The description discloses important behavioral traits beyond the annotations: it runs algorithm rules first, enforces monthly budget, and records posts for tracking. It also notes that quote posts are Enterprise-only, which is a critical constraining detail not in annotations. However, it doesn't detail the exact effects of posting (e.g., irreversibility) beyond the budget, though annotations already indicate it's non-read-only and non-destructive.

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?

The description is well-structured, starting with a clear verb and purpose, then detailing key rules, budget, and alternative tools in a compact paragraph. It is front-loaded with the main action and alternatives, and every sentence adds value without redundancy.

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 the tool's complexity (14 parameters, nested objects, algorithm rules, and budget), the description effectively communicates the major constraints and side effects. It covers the algorithm checks, media constraints, budget, and tracking, which is comprehensive. However, it doesn't describe the return value (no output schema), which might be a minor gap, but the detailed annotation and schema coverage compensate.

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?

With 93% schema description coverage, the schema already documents most parameters. The description adds context for `thread` (posts as replies, no For You reach) and `dry_run`, and mentions budget impacts for URLs, but it doesn't explain the `long_post_limit` beyond schema. However, given the high coverage, a 4 is justified as it adds clarity on key parameters.

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 clearly states the tool's purpose: creating an original post on the authenticated account, with options for a self-thread and media. It distinguishes itself from siblings like `reply` (which posts replies) and `handoff` (for quote posts) by explicitly mentioning those alternatives.

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 provides explicit guidance on when to use this tool vs. alternatives: use `thread` for follow-up replies, and use `handoff(kind="quote")` for quote posts. It also details the dry_run option for planning, making it clear when to use it for previewing.

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