fetch_users

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explicitly states this is a read operation ('Gets'), specifies the return format (JSON list), and mentions error handling ('error message if the request fails'). While it does not discuss authentication or pagination, for a simple parameterless list, this is reasonable disclosure.

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 concise, with a clear first sentence stating the purpose, a brief note on user types, and a structured 'Returns' section. Every sentence adds value, and the format is easily scannable for an agent.

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 simple tool with no parameters and no output schema, the description is complete enough. It states what the tool does, what it returns, and even provides context about the three user types. There are no missing critical details for an agent to invoke it correctly.

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?

The tool has zero parameters, and the schema covers all of them (none). According to the rubric, a tool with 0 parameters gets a baseline score of 4. The description adds no parameter details, but none are needed.

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 clearly states the tool 'Gets the list of all users' from the server, specifying the resource (users) and the action (get). It also mentions the JSON format, and the reference to 'all users' differentiates it from other tools like fetch_inventory_items or fetch_bill_records.

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 usage: if you need the list of all users, use this tool. However, it does not explicitly mention when not to use it, alternatives, or prerequisites. It relies on the tool name and the sibling context for differentiation, but lacks explicit guidance.

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