create_thread

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

No annotations are provided, so the description carries the full behavioral burden. It says nothing about required permissions (e.g., thread-creation rights), whether the creator auto-joins the thread, or side effects. The default auto-archive behavior lives only in the schema, not the prose.

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?

A single, front-loaded sentence with no filler. It is efficient, though slightly terse given the tool's five parameters and mutation semantics.

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?

With no annotations and no output schema, the description is the only place to convey behavioral context, and it omits permission requirements and post-creation effects. It is minimally adequate because the schema fully documents all parameters, but incomplete for a mutation tool.

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 baseline is 3. The description adds only a mild hint by mapping messageId presence to 'message thread' creation, but adds no syntax or format detail beyond the schema's own descriptions.

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?

States a specific verb and resource ('Start a new thread') and distinguishes the two creation modes: standalone channel thread vs. a thread attached to an existing message. That differentiation is useful, though it doesn't explicitly contrast with adjacent siblings like join_thread or modify_thread.

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 phrase 'in a text channel or from a specific existing message' implies the applicable context, but there is no explicit when-to-use/when-not guidance or routing to alternatives such as create_forum_post for forum posts. Usage is inferable rather than stated.

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