whatsapp_get_chat_picture

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

Annotations already declare readOnlyHint=true and openWorldHint=true, matching 'Read-only'. The description adds genuine behavioral context beyond those: it states the return content (picture URL and ID) and discloses failure modes ('fails if the chat has no picture or it is hidden by privacy settings'), which an agent cannot infer from annotations alone.

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, front-loaded with the primary action, then read-only status, then return/failure behavior. No filler; every sentence earns its place.

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?

With no output schema, the description compensates by naming the return values (URL and ID) and the failure conditions. Combined with annotations covering the safety profile, an agent has everything needed to call this 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?

Schema description coverage is 100% for the single chatId parameter. The description's 'by its JID' slightly reinforces the expected identifier format but adds little beyond the schema's own 'Chat JID' description, 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?

States a specific verb (Get) and resource (profile picture of a chat), and clarifies the resource is 'a contact or a group'. This clearly distinguishes it from write siblings like whatsapp_set_group_picture and whatsapp_set_community_picture.

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 read-only nature and resource are clear, implying straightforward usage, but the description offers no explicit guidance on when to use this versus alternatives (e.g., whatsapp_get_chat_business_profile or whatsapp_get_user_profile) and no prerequisites. Usage is implied rather than stated.

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