List login profiles

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the trailing 'Read-only.' largely restates structured data. The genuinely additive information is that profiles are machine-local and the tool wraps `tailscale switch --list`, which helps an agent reason about scope but is thin behavioral context.

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 and very short, with the core purpose in the first clause. The closing 'Read-only.' is redundant with the readOnlyHint annotation and could have been spent on return-value detail instead, but the payload is otherwise waste-free.

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 zero-argument, read-only list command with full annotation coverage, the description covers purpose and execution context adequately. With no output schema, a hint about the shape of the returned profile list would have closed the remaining gap.

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?

The tool takes zero parameters, so per the baseline this dimension starts at 4 and there are no parameter semantics for the description to clarify or omit. Nothing here degrades the score.

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 precise verb+resource ('List the Tailscale account/login profiles') and pins the scope to 'on this machine', with the backing CLI command for corroboration. It is unambiguously distinct from sibling tailscale_switch_profile, which mutates the active profile rather than listing them.

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?

Usage is only implied — an agent can infer this is the discovery step before tailscale_switch_profile, but the description never says when to prefer this tool or that switching is the natural follow-up. No exclusions or prerequisite conditions are given.

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