tailscale_validate_aclValidate a Tailscale ACL policy before applying it. Checks the policy text and returns any errors found, or confirms it is valid.
Validate an ACL policy without applying it. Returns any errors found, or confirms the policy is valid.
| Name | Required | Description | Default |
|---|---|---|---|
| policy | Yes | The full ACL policy text to validate |
Changes observed during successful MCP inspections.
v0.13.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds value by disclosing the return behavior (errors found or valid confirmation), which matters since no output schema exists, though it does not say whether validation is syntactic only or checked against live tailnet state.
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 short sentences with zero filler; the non-mutating scope is front-loaded before the return-value statement. Nothing can be trimmed without losing meaning.
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-parameter, read-only validation tool with annotations covering safety and a description covering the return outcome, this is nearly complete. The only gap is not clarifying whether validation is purely syntactic or evaluated against current tailnet configuration.
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% and the single 'policy' parameter is documented as 'The full ACL policy text to validate'. The description adds nothing beyond the schema, so the baseline 3 applies for a fully documented single-parameter tool.
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 (validate) and resource (ACL policy) and adds the critical scope qualifier 'without applying it', which separates it from the mutating siblings tailscale_update_acl and tailscale_set_* tools. An agent can tell this is a non-mutating check without opening the schema.
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 'without applying it' implies the intended use case (check a policy before committing it), but there is no explicit when-to-use guidance or routing against close siblings such as tailscale_preview_acl, tailscale_diff_acl_access, or tailscale_get_acl. Usage is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.