tailscale_acl_preview

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

No annotations are provided, so the description carries full burden. The word 'preview' implies a non-destructive read-only operation, but the description does not explicitly state it has no side effects or specify any behavioral traits beyond the implied read-only nature.

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 redundant words. The core action and use case are front-loaded, making it easy for an agent to quickly understand the tool's purpose.

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?

The description is minimal given the tool has a nested schema (policy object) and no output schema. It does not describe the return format or what the preview result looks like. With no output schema, the agent lacks information about what to expect from the 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?

All parameters have descriptions in the input schema (100% coverage). The description reinforces the role of 'previewFor' by mentioning 'specific user or IP', but adds no additional meaning beyond what the schema already provides. Baseline 3 is 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 clearly states the tool previews ACL policy for a specific user or IP, distinguishing it from siblings like tailscale_acl_test which likely tests current policy. The verb 'preview' and resource 'ACL policy' are specific and the scope ('for a specific user or IP') is explicit.

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 description says 'Useful for testing before applying changes,' which implies when to use it. However, it does not explicitly state when not to use it or contrast with alternatives like tailscale_acl_test or tailscale_acl_validate, leaving some ambiguity.

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