Set device routes

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

The description adds significant behavioral context beyond the annotations: it discloses that the operation is a full replacement ('Replaces all currently enabled routes') and instructs the agent to pass the complete desired list. This aligns with and reinforces the destructiveHint and idempotentHint annotations 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?

The description is two sentences with no filler. The primary action is front-loaded, and the critical replacement behavior is stated immediately after, making the most important information easy to spot.

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 two-parameter mutation tool with no output schema, the description is complete: it states the action, the resource, and the critical destructive/replacement behavior. The schema covers parameter formats (including device ID provenance), and annotations cover safety flags, so nothing needed for correct invocation is missing.

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 both deviceId and routes already documented in detail. The description reinforces the routes semantics ('pass the full list of routes you want enabled') but does not add meaning beyond what the schema already provides, so the baseline 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 states a precise action ('Set the enabled subnet routes for a device') with an explicit resource and scope, and clarifies that it replaces all currently enabled routes. This clearly distinguishes it from sibling get_* tools like tailscale_get_device_routes and other set_* tools operating on different resources.

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 makes the usage context clear: use it to configure the full list of enabled routes for a device. The explicit warning to pass the full list is valuable operational guidance. However, it does not explicitly name tailscale_get_device_routes as the read alternative or state when not to use this tool, though sibling names make this relatively obvious.

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