Reply to Forum Topic

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

Annotations already mark it as non-read-only and non-idempotent; the description adds useful context beyond that by disclosing the login requirement and SSO behavior. It does not detail failure behavior or duplicate-posting risk, but the annotation baseline lowers the burden.

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?

Two concise sentences with no filler. The core action and identifier format are front-loaded, and the auth prerequisite is stated in the second sentence without extra detail.

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?

The description covers the action, target identification, and the non-obvious SSO/auth prerequisite. It is sufficient for an agent to invoke the tool, though it could add a note about what happens when no session exists or that replies are publicly visible.

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 input schema leaves 'topic' undocumented, and the description fills this gap by stating it accepts an id or URL. For text, html, and dry_run, the schema descriptions already carry the meaning, so the description wisely avoids repetition.

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 states a specific action ('Post a reply') and resource ('forum topic') and clarifies the identifier can be an id or URL. It is immediately distinguishable from sibling tools like pm_reply or reply_mod_bug because 'forum topic' names the exact target.

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?

Usage context is implied: replying to a forum topic, with the prerequisite of a logged-in web session and automatic SSO. However, the description does not state explicit when-not-to-use conditions or alternatives such as reply_mod_bug or post_mod_comment.

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