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

Annotations already declare a safe read (readOnlyHint, idempotentHint, non-destructive), and the description adds genuinely new behavioral facts: owner-only authorization that the backend enforces, server-side filtering of disabled/deleted/plan-less accounts rather than upstream, and an `excluded` count reporting how many were dropped.

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 what is returned and the owner-only constraint, which are the two facts that matter most. It is dense but slightly redundant: 'Never guess or construct a userId' is restated by 'An account that is not listed cannot be passed as `userId` either', and the seven-tool enumeration is long though useful.

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 output schema, the description usefully enumerates the returned fields and explains the `excluded` counter, which an agent would otherwise misread. It stops short of describing pagination metadata (totals/page counts) for a paginated list, leaving that inferred.

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% (page, keyword, pageSize are all documented), so the schema carries the parameter burden and baseline 3 applies. The description adds no syntax or interaction guidance for those parameters — notably it doesn't say how `keyword` interacts with the active-only filter or how pagination relates to the `excluded` count.

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?

States a specific verb and resource (list the active sub-accounts under your agency) and immediately names the fields returned (id, name, email, plan, state). It is unmistakably distinct from `team_members_list`, which it explicitly contrasts as listing MANAGERs on your own account rather than separate accounts.

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?

Gives explicit routing: this is the source of a `userId`, and it enumerates the seven tools that consume one. It also gives the negative case (an id from outside this list is refused, never guess one) and closes off out-of-scope operations by pointing creation/disabling/licensing to the web app.

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