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

Annotations already establish this is a non-read-only, non-idempotent, non-destructive, closed-world mutation. The description adds genuinely non-obvious context: the media is referenced rather than re-uploaded and no additional quota is consumed because the source was already counted. It does not say whether the draft needs a separate publish step or what permissions are required, but the quota/quoting behavior is valuable added context.

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?

Three tight sentences with the core action front-loaded and the quota rationale second. The opening line largely restates the annotation title ("Create a story draft from an existing post or video"), which is mild redundancy, but nothing else is wasted.

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 4-parameter mutation tool with no output schema and full annotation coverage, the description supplies the key non-obvious facts: draft-not-published output, media referencing, and no repeat charge. Missing details about the return payload and platform selection limits are minor given there is no output schema to explain.

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 only 50%, so the description must compensate. It does clarify that `source` selects between generated_posts (default) and video_posts, which is more precise than the schema's generic "Source table" note, and the schema itself covers caption fallback. The `platforms` parameter and the postId format constraint get no additional explanation from either source.

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 ("Convert a post or video into a Story") and immediately clarifies that a draft is produced from existing media rather than new media. This cleanly separates it from createStory/createPost siblings, since the agent can tell conversion-of-existing-content apart from net-new creation without opening either schema.

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 (use this when you already have a source post/video and want to reuse its media), and it gives concrete routing advice for the `source` parameter. However it never states when NOT to use it or names an alternative such as createStory for cases with no existing post.

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