Tailscale version

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is fully covered. The description's 'Read-only' largely restates that, and adds only the underlying CLI invocation; it does not describe the shape of results or latency of the optional upstream check.

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?

A single compact sentence that front-loads what is reported and appends the optional behavior. Every clause earns its place with no filler.

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 trivial zero-required-parameter, single-parameter tool with no output schema, the description gives enough to call it correctly, and the annotations carry the safety profile. It could briefly note that the upstream check requires network access, but nothing essential 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%, so the schema already documents checkUpstream as 'Also check the latest available release.' The description's 'optionally checking for updates' adds a small amount of framing but no format, cost, or network-behavior detail beyond what the schema provides, so the baseline of 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 (Report) and resource (client and daemon versions), and even names the underlying command (`tailscale version --json`). This clearly distinguishes it from siblings like tailscale_status, tailscale_server_info, and tailscale_whoami, which report different data.

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 phrase 'optionally checking for updates' implies when the checkUpstream parameter matters, but there is no explicit guidance on when to prefer this tool over tailscale_status or tailscale_server_info, nor any stated prerequisites. Usage is implied rather than stated.

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