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

Annotations only cover the read-only/idempotent safety profile, and the description adds substantial behavior on top: newest-first ordering, the meaning of an empty list, the 404 failure mode, the one-hour edit window that explains why histories are often short, and per-version billing. These are exactly the facts an agent needs to interpret results and anticipate cost.

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?

Six short sentences, front-loaded with purpose and result shape before failure and cost details. The only waste is near-duplication between 'Billed per version returned' and 'Costs 1 credit + 1 credit per post returned,' which could be merged into one clause.

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 single-parameter read tool with no output schema, the description covers return ordering, empty-result semantics, error behavior, and cost. Nothing material is left for the agent to guess before invoking it.

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 100%, and the schema already explains that the id accepts digits or a full x.com/twitter.com status URL. The description adds nothing further about the identifier, so the baseline 3 applies.

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 first sentence names a specific verb and resource ('Get the edit history of an X post'), which cleanly separates it from get_x_post, get_x_thread, and get_x_quotes in the sibling list. The second sentence further pins down what is returned ('every version of an edited post, newest first, including the current one').

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 clear selection context: use it to reconstruct edits, and 'an empty list means the post exists and was never edited' tells the agent how to interpret a negative result. It does not explicitly say to use get_x_post for the current version instead, so the sibling routing is implied rather than stated.

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