create-thread

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

Annotations already signal this is not read-only, not idempotent, and not destructive. The description adds the side-effect notion that it can optionally notify users or groups, but does not disclose the default notify-everyone behavior when recipients is omitted or the displayInInbox unarchive behavior. No contradiction with annotations.

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?

Three short sentences with the core purpose front-loaded. No filler, though 'Requires a channel ID, title, and content' is partly redundant with the schema's required list. It remains easy to parse.

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 creation tool with a rich parameter schema and an output schema, the description plus structured fields is sufficient for an agent to invoke it. It could be more complete about notification defaults and inbox behavior, but those are covered in the parameter schema, and return values are handled by the output schema.

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 structured parameter descriptions already do the heavy lifting. The tool description largely restates required fields and optional notification rather than adding meaning beyond channelId, title, content, recipients, groups, or displayInInbox.

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?

Description uses a clear verb and resource: 'Create a new thread in a workspace channel.' It names the primary required inputs, so an agent knows what object this tool acts on. It does not explicitly contrast with the sibling create-conversation, so it stops short of full sibling differentiation.

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 when-to-use guidance versus alternatives such as create-conversation or reply. The statement of required fields helps invocation but does not tell the agent when this tool is the correct choice or when it should choose another sibling.

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