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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=false, so the safety profile is largely structured. The description goes beyond that by explaining that the post is irreversible once dry_run=False and is visible to the instructor, and that it posts as private/secret by default — context an agent cannot get from the annotations. It stops short of describing auth requirements or failure modes.

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 short sentences, front-loaded with the irreversible/visibility warning before the workflow instruction. No filler, no repetition of schema field definitions.

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 an output schema present and annotations covering destructiveness, the description supplies the two pieces the structured data cannot: the dry-run confirmation protocol and the private-by-default visibility. It does not mention error behavior or whether the preview is identical to the eventual post, a minor gap 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% and each parameter already carries its own description, including dry_run. The description restates the dry_run workflow, which reinforces rather than adds new parameter-level meaning, so the baseline 3 applies.

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 ('Post a new question to a course's Q&A board'), which pins down both the action and the target surface. The Q&A board framing implicitly separates it from add_discussion/add_discussion_post siblings without needing to open a schema.

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?

Gives an explicit mandatory workflow: call with dry_run=True, show preview, then re-call with dry_run=False only after user confirmation. It is clear about how to invoke safely but never names the alternative sibling tools (add_discussion, add_discussion_post) or states a condition for choosing the Q&A board over a forum.

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