Pin or unpin a chat

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

The description adds behavioral context by stating that pinning applies 'on the linked devices' and that pinned:false reverses the operation. This supplements annotations like idempotentHint and readOnlyHint without contradicting them.

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?

A single front-loaded sentence contains the core action, the effect on linked devices, and the unpin mechanism. There is no redundant or filler content.

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 toggle operation, the description covers both directions of the action and the schema covers parameter meanings. No output schema is needed for an operation whose success is evident, and annotations already convey safety and idempotency.

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 schema already documents all three parameters, so baseline is 3. The description goes beyond by explaining that pinned:false triggers unpinning, which clarifies the toggle semantics beyond the schema's 'Default true'.

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 verb and resource: 'Pin a chat to the top on the linked devices, or unpin it'. This clearly distinguishes it from sibling chat-related tools like archive_chat or mute_chat by focusing on the pin/unpin action.

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 gives clear context for use: pin a chat or unpin by setting pinned:false. It doesn't explicitly name alternatives or exclusions, but the toggle behavior is unambiguous and self-contained.

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