reply_to_thread

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

With no annotations, the description carries the load and explains key behaviors: is_private makes the reply staff-only, is_anonymous hides the author, parent_id nests replies, and content must be in Ed XML format. It doesn't mention permissions or side effects, but the main behavioral traits are disclosed.

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 well-structured: a concise opening sentence, the XML requirement, and a clear bullet-style list of args. Every sentence adds value without unnecessary fluff, and the length is appropriate for the parameter count.

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?

Given the tool's complexity (6 params, no annotations) and the presence of an output schema, the description covers all necessary aspects: how to format content, parameter meanings, privacy/anonymity options, and nesting mechanics. It leaves no significant gaps for an agent to invoke it correctly.

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%, but the description provides detailed meanings for all six parameters, including defaults and restrictions. This fully compensates for the schema's lack of descriptions, adding clear semantic value.

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's purpose: 'Reply to a thread with a comment or answer.' It specifies the action (reply), the resource (thread), and optional type (comment/answer), which distinguishes it from sibling tools like create_thread or edit_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?

It gives usage context by explaining where to get thread_id ('from list_threads or search_threads'), and clarifies that 'answer' type only works on question threads. It doesn't explicitly exclude alternatives, but the purpose is clear enough to guide selection.

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