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

The description discloses no side effects, idempotency, or potential errors. It does not mention that pinning changes chat ordering or that unpinning might be needed for reversal. The annotations do not add behavioral detail.

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?

The description is succinct but misleading due to the enumeration of multiple actions. It attempts to be structured but sacrifices clarity for brevity.

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?

The description lacks essential context: it does not specify that the tool is for pinning, does not explain the response or side effects, and leaves parameter usage undefined. It is incomplete for a straightforward action.

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?

The description only mentions chat_jid as required but does not explain its meaning or the roles of 'account' and 'duration_secs'. Since the schema has no descriptions, the description fails to clarify parameter semantics.

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 says 'Change a chat's state' and lists multiple actions (archive/unarchive, pin/unpin, mute/unmute), but the tool name is 'pin' and the schema lacks an action parameter. This ambiguity makes it unclear that the tool specifically pins a chat.

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 merely states 'Requires chat_jid' without explaining when to use this tool versus sibling tools like whatsapp_chat_unpin or whatsapp_chat_archive. It provides no context for selection or prerequisites beyond a required parameter.

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