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

Annotations are all false, so description carries full burden. It discloses that it returns a QR code or pairing code, that it is asynchronous (polling required), and that it explains upgrades if ineligible. Re-authentication behavior is also disclosed. 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?

Five sentences, each earning its place: purpose, mode explanation, polling instruction, prerequisites, and re-auth usage. Front-loaded with the core action, no filler.

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 two-param tool with no output schema, the description covers return behavior (QR/pairing code), next steps (polling), and eligibility conditions. No critical information is missing for correct invocation.

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?

Despite 100% schema coverage, the description adds meaningful context: explains the default QR mode, the phone_number toggling to pairing code, and account_id's role in re-authentication. This goes beyond the schema's already detailed property descriptions.

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?

Clearly states the tool connects/reconnects a WhatsApp account, specifying the resource (WhatsApp) and the action (connect). It distinguishes itself from siblings like account_connection_status by explicitly mentioning polling after initiation, and from telegram_connect by being WhatsApp-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?

Provides explicit guidance: when to use phone_number (when QR cannot be displayed), when to use account_id (re-authenticate existing account), and directs to poll account_connection_status afterward. Also states prerequisites (active trial/subscription and free slot) and what happens if unmet.

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