List conversations

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

Beyond the read-only annotations, the description discloses ordering (latest first), returned fields, exclusions (publication chats left out), and the important side-effect clarification that reading the list does not mark anything read. It does not discuss pagination behavior or rate limits in the description, though cursor pagination is covered by the schema.

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 front-loaded with the core action and then efficiently adds the inbox scope, returned fields, exclusions, side-effect behavior, and next-step guidance. Every sentence contributes useful information without repetition.

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?

Even without an output schema, the description explains the returned contents, ordering, exclusion rules, and read-state behavior. Combined with annotations covering safety and schema covering parameters, an agent has enough information to call and interpret this tool 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?

The schema has 100% description coverage for both parameters, so it already documents cursor and unread_only. The description does not add parameter-specific meaning beyond that baseline, which is appropriate for a fully documented two-parameter schema.

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 states a specific resource (direct-message conversations) and scope (Substack chat inbox, latest first, with last message). It clearly distinguishes this from publication chats by explicitly excluding them and explains the returned fields.

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 gives useful context for using the returned conversation_id with get_conversation or send_message, and it clarifies that publication chats are excluded. However, it does not explicitly say when to use this tool versus sibling tools such as get_unread_counts, leaving some alternative-choice guidance implicit.

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