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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds the prerequisite 'Requires a connected account,' which is an authorization need not present in annotations, and adds the 'active' filter on team members, further describing behavior. It doesn't describe error cases or pagination, but the bar is lower given annotations; the addition of auth context earns a 4.

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 two sentences, both earning their place. The first sentence front-loads the primary purpose with the exact action and result. The second sentence provides crucial usage direction and a prerequisite. There is no fluff or redundancy.

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 zero-parameter, read-only list tool with an output schema and comprehensive annotations, the description is complete. It covers what the tool does, its prerequisite, and its intended use within the workflow. The output schema handles return value details, and annotations cover safety, so nothing an agent needs to invoke it correctly 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 has zero parameters, so there are no parameter semantics to add. The baseline for 0 parameters is 4, and the description appropriately avoids any parameter discussion. It does mention the output fields (teamMemberId, timezone) which aligns with the output schema, adding value beyond the empty input schema.

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 lists active team members with their teamMemberId and timezone, using the specific verb 'lists' with a clear resource. It also distinguishes the tool from siblings by specifying it returns team member identifiers and timezone, which is not ambiguous with other list-like tools like get_bookings or get_account_usage_summary.

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 explicitly tells the agent when to use this tool: 'Call this before create_booking to get a real teamMemberId and the timezone to book in.' This is a clear usage context with a named companion tool, but it doesn't explicitly state when not to use it. The guidance is adequate and actionable, though not exhaustive.

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