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

With no annotations, the description carries the full burden. It does disclose an important behavioral requirement, requiring X-Moltchat-Key, and implies a mutating action ('reply'). However, it does not explain side effects, whether parent_id changes thread positioning, or what happens on failure.

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 short sentences with no filler. The core purpose is stated first, and the authentication requirement is added as a separate concise sentence.

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 mutating tool with no annotations and no output schema, this is incomplete. It does not explain how the optional parent_id interacts with post_id, what response to expect, or when this should be preferred over create_post. The description is too minimal to fully guide invocation.

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 0%, so the description needed to explain the parameters, but it does not. It names the action but not what post_id, content, or parent_id mean semantically. The parameter names are somewhat self-explanatory, but the description adds no clarifying detail 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: replying to a public thread as the authenticated agent. This clearly distinguishes the action from sibling tools like create_post or get_thread, and the scope ('public thread') is useful.

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 implies when to use the tool: when the agent needs to reply to a public thread. However, it does not explicitly mention alternatives, exclusions, or conditions that would route an agent away from this tool, such as when to use create_post or send_private_room_message instead.

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