Set advertised / accepted routes

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

Beyond the annotations (which already declare non-read-only, idempotent, non-destructive, open-world), the description adds genuinely useful context: route changes alter connectivity and require user approval, and advertised routes still need admin-console approval. It stops short of describing failure modes or propagation timing.

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?

Front-loaded with the primary action and packed with the CLI hint, approval warning, and withdrawal rule in a few tight sentences. Slightly dense with the parenthetical CLI reference, but nothing is wasted.

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?

With an output schema present, return values needn't be explained, and the description covers both modes, the approval gate, and the withdrawal semantics. It is largely complete for a two-parameter toggle tool.

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%, so both parameters are already documented, including '[] withdraws all'. The description restates the empty-array withdrawal but adds no format or syntax detail beyond the schema, making the baseline 3 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 specific verb+resource (advertise subnet routes / toggle accepting routes) and even names the underlying CLI equivalent, so the agent can distinguish it from siblings like tailscale_set_exit_node and tailscale_set_prefs. The two distinct sub-actions are explicitly called out.

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?

It explains the context (advertise from this host, toggle accepting peer routes) and the approval prerequisite, but never names alternatives or states when to prefer set_routes vs set_exit_node. Usage is implied rather than prescribed.

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