tailscale_set_device_routes

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

Annotations already indicate idempotent and non-destructive. Description adds critical context: 'Replaces all currently enabled routes', clarifying idempotent behavior and that it's a full replacement. No contradictions.

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?

Two sentences, no fluff. First sentence states purpose, second adds crucial behavioral nuance. Front-loaded with actionable information.

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 low complexity (2 params, no output schema), the description is sufficient. Explains replacement behavior and required input. Could mention getting current routes first, but not essential.

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 has 100% coverage and already describes both parameters well (deviceId and routes with example). Description adds marginal value by reiterating replacement aspect, but doesn't provide additional parameter semantics beyond schema.

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?

Clearly states the action (set), the resource (device routes), and the key behavior (replaces all enabled routes, pass full list). Distinguishes from sibling tools like tailscale_get_device_routes and tailscale_set_device_tags.

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 to pass the full list of routes, implying not additive. Lacks explicit mention of when to use vs get routes or alternatives, but provides clear usage context for the replacement behavior.

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