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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the 'all' scope, but does not disclose additional behavioral details such as pagination, rate limits, or response shape; this is acceptable for a zero-parameter read-only endpoint, but it does not go beyond the annotations.

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 three words, front-loaded, and contains every piece of information needed at the top level. No filler or redundant explanation exists.

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?

Given the zero-parameter input, the presence of an output schema, and annotations covering read-only/idempotent behavior, 'Get all users' is complete enough for an agent to select and invoke the tool correctly without missing information.

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?

There are zero parameters and the input schema is empty, so there is nothing for the description to explain. Per the baseline for tools with no parameters, the description's lack of parameter details is not a deficiency.

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 states a specific action ('Get') and resource ('all users'), clearly distinguishing it from sibling tools like getPost/getPosts and createPost. The word 'all' also communicates the endpoint's scope, leaving no ambiguity about what is returned.

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 use when the caller needs the full list of users, but it does not explicitly state when to use this tool versus alternatives or mention any exclusions. Since there is no sibling that fetches a single user, the lack of explicit guidance is less harmful, but guidance is still only implied.

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