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

With no annotations, the description carries the full burden. It mentions 'Billing per call: 1 Credits' which is a useful operational hint. However, it doesn't disclose behavior like whether it requires authentication, rate limits, or what happens when a contact is not found. The description adds minimal behavioral context beyond the billing note.

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 short and front-loaded, but it repeats the title 'Get User Info/Details'. The billing sentence adds obscure technical wording 'Billing per call: 1 Credits.' It could be more packed with meaningful details, but it's not verbose.

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 has one parameter, no annotations, no output schema, and a vague description. It's a simple tool but the description fails to explain what information is returned or how to interpret the response. The example parameter helps slightly, but overall the agent likely lacks clarity on what 'User Info' means and when to use 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%, with the single parameter 'body' having an example. The description itself doesn't add parameter detail, but the schema's example provides the required format. Since coverage is complete, a baseline of 3 is appropriate; the description doesn't add extra semantic value.

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 says 'Get User Info/Details' which is only slightly more specific than the tool name and title. It doesn't state what specific user information is retrieved (e.g., name, presence, etc.), nor does it distinguish itself from siblings like post_getAbout or post_getProfilePicUrl.

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 provides no guidance on when to use this tool versus alternatives. Sibling tools exist (getAbout, getProfilePicUrl) but no cross-referencing or when-to-use guidance is given. The billing note mentions 1 credit per call, which is a cost hint but not usage guidance.

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