Get User Account Summary

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

Annotations already declare readOnly, idempotent, open-world, and non-destructive, so the safety profile is covered. The description adds real value beyond that: it requires a TweetAPI API key, issues exactly one request per call, usually costs 1 unit, and returns a per-call cost estimate. It stops short of describing pagination or failure behavior, keeping it below a 5.

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: purpose and payload first, sibling routing second, operational constraints last. Every clause carries information (fields returned, alternative tool, auth, cost) with no 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?

For a single-optionality-free parameter read tool with a full output schema, the description covers everything an agent needs to select and invoke it: what it returns, how to identify the target, what it costs, and which sibling to use instead. Return-value details are correctly left to the output schema.

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% and the schema already documents that the username field accepts a plain username, an @handle, or a profile link such as https://x.com/jack. The description restates the same three forms without adding format rules or edge cases, so the schema is doing the heavy lifting — 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?

States a specific verb ("Fetch") and a specific resource ("About this account details") and enumerates the contents (location, verification, username history, affiliates, creation method). It explicitly distinguishes itself from the regular profile tool tweetapi_user_by_username, so the agent can differentiate it from siblings without opening a 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?

The description names an alternative (tweetapi_user_by_username) and the condition that selects it ("for the regular profile"), making the use/use-not boundary explicit. The accepted identifier forms (username, @handle, profile link) further clarify the calling context.

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