Look up X user profiles by usernames or numeric IDs, up to 100 per call, to retrieve account details via the X API.
Look up user profiles by usernames or by numeric IDs (up to 100). Billed per user.
| Name | Required | Description | Default |
|---|---|---|---|
| ids | No | ||
| account | No | X username of an authorized account (see list_accounts). Omit to use the default account. | |
| usernames | No |
Changes observed during successful MCP inspections.
v0.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnlyHint and openWorldHint, so safety is covered. The description adds a genuinely non-derivable behavioral fact: the call is billed per user, which materially affects how an agent should batch lookups. It stops short of 5 because it says nothing about auth/permission requirements or partial-failure behavior for unknown usernames.
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 sentences, front-loaded with the lookup keys, and the billing caveat placed last where it belongs. 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 three-parameter read tool with no output schema, the description covers the core lookup behavior and cost, but omits the account parameter, any indication of what profile fields come back, and how unknown or duplicate identifiers are handled.
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 33%, so the description must compensate, and it does partially: it clarifies that ids are numeric identifiers and that usernames are the alternative key, plus the 100-item cap (already in maxItems). It says nothing about the undocumented account parameter, and its "numeric IDs" phrasing slightly tensions with the schema's string-typed items.
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 names a specific verb and resource ("Look up user profiles") and states the two accepted lookup keys (usernames, numeric IDs), so the agent knows exactly what the tool returns conceptually. It does not distinguish itself from siblings like get_me or get_user_relations, so it stops short of a 5.
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 explains how to call it (by usernames or IDs) but never when to prefer it over alternatives such as get_me for the authenticated user or search for discovery. No prerequisites, exclusions, or sibling routing are given, so usage must be inferred.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.