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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds useful behavioral context beyond annotations: the concrete cost of $0.05 USDC via x402 and that the returned data includes full text content and date for each post.

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?

Two short, information-dense sentences with no filler. The main operation and output are front-loaded, and the cost note is placed separately but still relevant to invocation.

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?

The tool is simple, has one well-documented parameter, and the description covers both the input (handle) and the expected output (three post texts and dates). The cost is disclosed, and the annotations cover safety and side effects. Nothing essential for calling the tool 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 description coverage is 100%, and the schema already documents the 'handle' parameter with an example and the note about the '@' prefix. The description does not add semantics beyond calling it an X handle, so the schema carries the parameter documentation burden.

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 uses a specific verb ('Retrieve') and names the resource ('three most recent posts (tweets) from a given X (Twitter) handle'), plus the exact count and fields returned. This clearly differentiates it from sibling tools like interzoid_x_profile or interzoid_recent_news, even without mentioning them by name.

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 implies a clear usage context: when an agent needs the three most recent posts and their text/dates for a given X handle. It does not explicitly name alternatives or exclusions, but the 'three most recent posts' phrasing is specific enough to guide selection.

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