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

Annotations already declare readOnlyHint=true and destructiveHint=false, yet the description adds substantive behaviour the annotations do not: results are permission-filtered, most users see everyone but 'limited managers' see only themselves and their own team members, and the list must not be presented as the complete account roster. That is exactly the kind of hidden-behaviour disclosure that prevents a downstream agent from making a false claim.

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?

Front-loaded with the one-line purpose, then a scannable bulleted trigger list, then a short caveat paragraph. Every sentence carries information an agent needs (identity of the resource, triggers, permission scoping) with 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?

An output schema exists so return values need no re-explanation, but the description still surfaces the key non-obvious fields and the critical completeness caveat about permission-scoped visibility. For a zero-parameter, read-only listing tool, nothing an agent needs to call or interpret it is missing.

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 takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly avoids inventing non-existent filter parameters such as name or email.

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 verb and resource ('Get a list of the account users') and immediately disambiguates the term by defining account users as 'the people who can log in to this fynk account'. This separates it from near neighbours such as list-account-team-members, find-document-users and get-user-info.

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 gives three concrete triggers under 'Use this tool when', including a downstream use case that names a sibling (attach-account-users-to-team), so the agent knows when this tool is the right call. It does not, however, state when *not* to use it or contrast it directly with the other user/team-listing tools, so it falls short of full alternative routing.

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