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

The only behavioral disclosure is 'Billing per call: 1 Credits,' which provides cost information but nothing else. There are no annotations, so the description should explain side effects, auth requirements, or return behavior; it does not. The reference to 'Group: userTweets' is cryptic and unhelpful.

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 brief, but the brevity comes from under-specification rather than efficient communication. It mostly repeats the tool name and adds a billing line, contributing no substantive information that would help an agent select or invoke the tool.

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?

With no annotations, no output schema, and minimal schema descriptions, the description has the full burden of providing context. It fails to explain the tool's purpose, parameters, return values, or limitations, making it completely inadequate for a tool with three parameters and many similar siblings.

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 0%, yet the description provides no explanation for the three parameters (userIds, proxyUrl, resFormat). The agent has no context to know what values to supply or how to format them, especially since the schema itself only gives titles and one example.

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 is essentially a tautology: 'Get usersByIdRestIds by V2' restates the tool name and title without explaining what the operation does. It does not specify what 'usersByIdRestIds' means or what resource it acts on, and it fails to distinguish itself from similar sibling tools like 'uerByIdRestIdV2' or 'userByScreenNameV2'.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention preferred use cases, prerequisites, or exclusions, leaving the agent to guess which of the many user-lookup tools to invoke.

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