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

Annotations already declare readOnly, idempotent, non-destructive, and open-world behavior, but the description adds substantial context beyond them. It discloses the return shape, the 404 condition for non-Article posts, and the credit cost including per-post returned, which is exactly the kind of behavioral information an agent needs before invoking it.

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 front-loaded with what the tool returns, then moves to usage, input caveats, error behavior, and cost. Every sentence carries useful information, and there is no repetition or filler.

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?

There is no output schema, but the description adequately explains the returned content: title, cover image, Markdown body, plain text, X blocks, and images. It also covers the key error case and cost model, making the definition complete enough for an agent to invoke it 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 100%, so the single id parameter is already documented as accepting digits or an x.com/twitter.com status URL. The description adds meaningful semantics by emphasizing the status link/id form and warning that an x.com/i/article/ link contains a different id, which prevents a likely invocation error.

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 states a specific verb and resource: read a long-form X Article in full, including title, cover image, body Markdown, plain text, blocks, and images. It clearly distinguishes this from a normal post by noting that a post sharing an Article has only a link as its own text, so an agent can tell it apart from sibling tools like get_x_post or get_x_thread.

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?

It gives clear triggering guidance: use it for any x.com post or link that shares an Article, and pass the status link or id. It also provides important exclusions, such as x.com/i/article links containing a different id and a 404 when the post is not an Article. It does not explicitly name get_x_post as the alternative for non-Article posts, which keeps it just below the top score.

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