Read Discussion

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

Annotations already declare readOnlyHint and idempotentHint, so the description adds context beyond that by explaining the flattened reply structure with a depth field. This is valuable behavioral detail not captured in the schema or 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?

Two concise sentences, front-loaded with the main purpose and no redundant wording. Every clause adds information about behavior or parameter effects.

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 output schema exists and annotations are complete, the description is sufficient. It explains both usage modes and the nesting behavior, making it complete for a read-only tool with two parameters.

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 coverage is 100%, so parameters are fully described, but the description adds meaning by explaining the behavior difference: omitting topic_id lists topics, while providing it returns the topic and replies. This goes beyond the schema's description of topic_id as 'omit to list topics' by clarifying the full output.

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 function: 'Read course discussions.' It distinguishes two modes: listing topics with only course_id, and retrieving a specific topic with replies using topic_id. This specificity differentiates it from sibling tools like post_discussion_reply, which is for writing.

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 description provides explicit usage context: 'With only course_id, lists the discussion topics. With topic_id, returns that topic and all its replies...' This tells the agent when to use each parameter. It does not explicitly name alternatives or exclusions, but the read vs. write distinction with sibling post_discussion_reply is clear.

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