tailscale_set_device_routes

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

Annotations already indicate destructive and idempotent behavior, but the description adds meaningful context by explicitly stating that existing routes are replaced and instructing the agent to pass the complete desired list. This goes beyond the structured annotations and clarifies the real-world effect.

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 two sentences with no filler. The core action is stated first, followed immediately by the critical behavioral caveat about replacing routes, making it highly efficient and easy to parse.

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 two-parameter, no-output-schema tool, the description covers the essential operational behavior: setting routes, replacing all current routes, and needing the full list. A brief pointer to get_device_routes as a prerequisite would make it fully complete, but the current description provides enough context for correct invocation in most cases.

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%, with the routes parameter already explaining that it is the full list and replaces existing routes. The description reinforces this behavior but does not add additional parameter-level detail beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Set') with a clear resource ('enabled subnet routes for a device'). It clearly distinguishes itself from 'get_device_routes' and other device configuration tools by specifying the action and object.

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 explains an important usage constraint: routes are replaced wholesale, so the caller must pass the full list. However, it does not explicitly tell the agent when to prefer this tool over alternatives or suggest using get_device_routes first, leaving some usage context 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.