Switch login profile

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

Adds genuinely non-obvious behavior beyond the annotations: that the switch changes which identity/tailnet controls the node, that user approval is required, and that the resulting status is returned. Annotations already declare non-read-only, non-destructive, non-idempotent, so the description's contribution is the impact/approval context. It stops short of disclosing reversibility, side effects on existing connections, or failure modes.

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?

Three tight sentences, front-loaded with the action, followed by the warning and the id source, ending with the return behavior. The CLI equivalent and warning glyph earn their place.

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 one-param mutation tool with an output schema, the description covers the identity impact, approval requirement, id provenance, and return signal. Nothing an agent needs to invoke it correctly 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 coverage is 100% and the single param already documents 'Profile id from tailscale_list_profiles', which the description repeats rather than extends. No added syntax, format, or edge-case meaning beyond what the schema states, so the baseline 3 applies.

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?

States a specific verb and resource ('Switch the active Tailscale account/login profile') and pins it to the exact CLI operation. It is clearly distinct from the read-only sibling tailscale_list_profiles and from unrelated setters like tailscale_set_prefs.

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 routes the agent to tailscale_list_profiles to obtain the required id, and flags the user-approval prerequisite. It does not, however, state when-not to use this (e.g. between connect/disconnect) or how it interacts with other profile-affecting siblings.

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