Star or unstar a WhatsApp message for your account only. Use message, chat, and sender IDs to update its starred status and return a success confirmation.
Star or unstar a message on this account. Only this account sees it. Returns a success confirmation.
| Name | Required | Description | Default |
|---|---|---|---|
| chatId | Yes | Chat JID | |
| starred | No | True to star, false to unstar | |
| senderId | Yes | Message sender JID | |
| messageId | Yes | Message ID |
Changes observed during successful MCP inspections.
v2.0.0Input schema / properties / chatId / descriptionPrevious value: -"Chat ID where the message is located"New value: +"Chat JID"Input schema / properties / messageId / descriptionPrevious value: -"ID of the message to star"New value: +"Message ID"Input schema / properties / senderId / descriptionPrevious value: -"ID of the message sender"New value: +"Message sender JID"Input schema / properties / starredAdded value: +{
+ "description": "True to star, false to unstar",
+ "type": "boolean"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations cover safety (readOnlyHint=false, idempotentHint=true, destructiveHint=false), but the description adds two pieces of context they don't: the effect is account-private ('Only this account sees it') rather than visible to other participants, and the call returns a success confirmation even though no output schema exists. It does not describe error behavior, which keeps it out of the top band.
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?
Three short sentences, no filler, and the core action is front-loaded before the visibility caveat and return-value note. Nothing to trim.
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 four-parameter mutation with no output schema, the description covers action, effect scope, and response shape. The remaining gap is that it never clarifies how message identity (messageId/chatId/senderId) must be assembled, which matters for a star toggle on a specific message.
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% with all four parameters documented, so the schema carries the semantics. The description adds only the star/unstar direction implied by the 'starred' boolean, which the schema already states explicitly. 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?
States a specific verb pair and resource ('Star or unstar a message'), and the boolean parameter makes the two directions clear. However, it does not distinguish itself from the similarly-scoped sibling whatsapp_pin_message, so an agent gets no help choosing between the two.
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?
There is no when-to-use guidance, no prerequisites (e.g. required messageId/chatId/senderId context), and no mention of alternatives such as pinning or marking read. The description simply restates the operation.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.