get_chat_member_count

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

With no annotations, the description carries the full burden. It correctly identifies a read operation ('get'), but does not disclose potential error cases (e.g., invalid chat_id) or any side effects. Since the tool is simple and an output schema exists, the lack of deeper behavioral disclosure is acceptable but not exemplary.

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 extremely concise: one sentence for purpose followed by a brief parameter breakdown. Every word contributes meaning, and the critical information is front-loaded.

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 tool with one parameter and an output schema, the description is almost complete. It could mention that the count is only available in certain chat types (group, supergroup, channel), but this omission is minor.

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 description adds significant value by explaining the chat_id parameter format ('Chat ID or @channel_username') and default behavior ('uses TELEGRAM_CHAT_ID if omitted'), which the input schema does not provide. Schema coverage is 0%, so the description compensates effectively.

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 uses a specific verb ('Get') and resource ('number of members in a chat'), making the tool's purpose immediately clear. It distinguishes itself from sibling tools like get_chat_admins and get_chat_info by focusing solely on the member count.

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?

No guidance is provided on when to use this tool over alternatives. There is no mention of prerequisites, chat type restrictions, or comparison with get_chat_info (which likely includes member count). The agent receives no context for selecting this tool.

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