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

Annotations already declare readOnlyHint=true, and the description adds behavioral context: it lists both inbound and outbound, orders by newest first, and uses cursor-based pagination. Also includes the Bird API endpoint. This goes beyond the annotation and helps the agent anticipate pagination behavior.

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. The first packs the key information (action, scope, direction, ordering, pagination type), and the second provides the API endpoint. No wasted words or redundancy with schema or annotations.

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?

For a simple read-only list tool with 2 optional params and no output schema, the description covers purpose, scope, ordering, and pagination. It does not explicitly describe the response shape, but 'cursor page' and the schema's reference to `next_cursor` imply a standard page structure. Overall, sufficiently complete given low complexity.

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%: both parameters (limit, starting_after) have descriptions in the input schema. The description does not add parameter-specific details beyond what the schema already provides, so 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?

The description states a specific action: 'List WhatsApp messages (inbound + outbound) for the workspace, newest first, as a cursor page.' It clearly names the resource (WhatsApp messages), scope (workspace), direction (inbound+outbound), and ordering (newest first), distinguishing it from sibling get/list tools like bird_get_whatsapp_message and bird_list_sms_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 usage for listing workspace WhatsApp messages with pagination. It does not explicitly state when not to use it or name alternatives, but the clear resource and 'workspace' scope provide enough context for an agent to select it over other list or get tools.

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