List chats

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds explicit behavioral disclosure: 'Read-only — sends nothing and does not mark anything as read.' This goes beyond the annotations by clarifying side effects (no marking as read). No contradictions.

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 compact sentences: first delivers the core purpose and return value, second provides usage context and alternatives. Front-loaded, no wasted words.

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 tool's complexity (6 parameters, no output schema) and rich annotations, the description adequately covers purpose, usage context, filters, pagination, and alternatives. It explains what is returned (list with previews and unread counter) and when to use it, making it complete for agent decision-making.

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%, so baseline is 3. The description mentions filters (items, types, unread) and pagination (limit/offset) but does not add new semantic information beyond what the schema already details (e.g., limits, defaults, types). The narrative summary is helpful but not additive.

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 explicitly states 'Returns a LIST of the account's chats' with details on content (last message preview, unread counter). It distinguishes from siblings by mentioning messenger_get_chat_by_id_v2 and the downstream tools that require chat_id, making the purpose clear and specific.

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 clear when-to-use guidance: 'Use it to find the needed chat_id before messenger_get_messages_v3, messenger_post_send_message or messenger_chat_read.' It also explicitly names an alternative for a single known chat: 'To get the details of a single known chat, use messenger_get_chat_by_id_v2.' This covers usage context and exclusions.

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