update_device

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

No annotations provided, so the description carries the full burden. It discloses the critical failure condition (only works when signal-mcp is primary), the sync behavior (name appears immediately across devices), the limitation (only secondary devices can be renamed), and the non-effect on messaging. This is comprehensive behavioral disclosure.

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?

Though longer than typical descriptions, every sentence serves a purpose. It front-loads the core action and then logically expands into usage context, constraints, and alternatives without redundancy. The structure is clear and efficient.

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?

Given the complexity of device management (linking, primary vs secondary, failure modes), the description is complete. It covers prerequisites, error conditions, how to get IDs, what it doesn't affect, and alternatives. No missing information an agent needs to call the tool 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 coverage is 100% with basic descriptions for both parameters. The description adds valuable context beyond the schema: device_id is a small integer, device 1 is always primary, and the name is the new display name. This enriches parameter understanding, though it doesn't add formatting constraints or new fields.

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 the tool renames a linked secondary device on a Signal account, specifying the exact action (rename) and resource (secondary device). It distinguishes from siblings by explicitly contrasting with remove_device (unlink) and update_profile (rename primary account), making the purpose unambiguous.

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?

Provides explicit when-to-use guidance: 'Use when you want to distinguish between multiple linked devices by a meaningful label.' Also gives when-not-to-use: 'Do NOT use to rename your own primary account — that is done via update_profile.' It directs users to list_devices for IDs and remove_device for unlinking, fully routing to alternatives.

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