join_chat

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

Annotations already declare this as a mutating, non-idempotent, non-destructive, open-world operation. The description adds that the target is a public channel/group and that it can be specified via username or invite link. It does not disclose side effects like becoming a member or duplicate-join errors, but given annotation coverage, this is a minor gap.

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 a single sentence that is front-loaded and free of filler. It conveys purpose and parameter semantics without 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 simple one-parameter join tool, the description provides purpose and parameter format. An output schema exists, so return values are not needed. It lacks guidance on when to use and potential failure modes, but overall it is sufficient for basic usage.

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 schema has 0% description coverage for the 'chat' parameter, but the description clarifies that string values are @username or invite links. This is essential for correct invocation. It does not explain the integer alternative, but the primary ambiguity is resolved.

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 joins a public channel/group via @username or invite link, using a specific verb and resource. This distinguishes it from siblings like leave_chat, create_group, and auth_submit_code. It also specifies the method of target identification.

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 explicit when-to-use guidance or alternatives are provided. The description implies use when the user wants to join a chat, but it doesn't mention exclusions (e.g., private chats) or name leave_chat as the counterpart. Context is clear but minimally developed.

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