update_device

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

Describes syncing across devices, immediate appearance, no effect on messaging, and the constraint that only secondary devices can be renamed. No annotations provided, but this is comprehensive.

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?

Single efficient paragraph, front-loaded with action, no redundant sentences, every sentence adds value.

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 rename tool with 2 params and no output schema, the description covers purpose, behavior, usage, limitations, and sibling differentiation fully.

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 coverage is 100% so baseline is 3. Description adds context: device_id is a small integer from list_devices, device 1 is always primary; name is 'New display name'. Exceeds baseline.

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 clearly states 'Rename a linked secondary device on your Signal account.' and distinguishes from siblings like list_devices, remove_device, and update_profile.

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?

Explicitly says when to use (to distinguish linked devices), when not to use (primary device, use update_profile), and provides alternatives (list_devices, remove_device).

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