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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds context about the output including unread counts and last message time, and notes that Threads items are public conversations. This is useful extra behavioral disclosure beyond the 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?

The description is concise, with three short sentences that front-load the primary purpose. Every sentence provides value: the first states the function, the second clarifies a channel-specific nuance, and the third mentions key output fields. No filler or redundancy.

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 tool has a clear list operation with well-covered annotations and output schema. The description covers the channel scope, mentions public Threads nuance, and key output fields, making it complete for a list operation. No critical information is missing.

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 has 100% coverage of parameter descriptions, including enums for status and channel. The description does not add any additional parameter semantics beyond what the schema provides, so it meets the baseline of 3.

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 lists messaging conversations across specified channels, using the verb 'List' with a specific resource. It also distinguishes from sibling tool get_conversation_messages by focusing on the list of conversations rather than individual messages.

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 implies the tool is for browsing conversations across multiple channels, which is clear. It does not explicitly exclude alternatives or mention when to use a different tool, such as get_conversation_messages for viewing messages within a conversation, so it lacks explicit exclusions.

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