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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description clarifies that returned participant user IDs are NOT chat IDs and can be reused for membership operations. This is valuable output-semantics disclosure that annotations do not provide.

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 front-loaded with purpose, then gives necessary resolution and output guidance. It is slightly dense and repeats some chat_id text also present in the schema, but every sentence contributes useful information.

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 read-only two-parameter tool with no output schema, the description compensates by explaining output ID semantics and how to resolve the required chat_id. It could mention the response shape more explicitly, but the essentials for correct invocation are covered.

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%, so the schema already thoroughly documents chat_id and account_id. The description adds usage emphasis like 'Resolve chat_id first' and 'Never pass...' but does not add substantive parameter semantics beyond the 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 states a specific verb and resource: 'List members of an exact group/multi-party chat.' It is clearly distinguished from sibling chat operations like adding/removing participants, and the first sentence immediately tells the agent what the tool does.

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 gives strong usage context: resolve chat_id first, obtain it from conversation listings, and never pass person name/user_id/message_id. It does not explicitly name alternatives, but the prerequisite and ID-type guidance make correct invocation clear.

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