tailscale_set_contacts

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

The description goes beyond annotations by detailing the parallel PATCH behavior and partial failure handling with response structure ({ applied, failed }). Annotations already indicate idempotentHint=true and destructiveHint=false, so the description adds valuable behavioral context. Score 4 for meaningful additional transparency.

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?

The description is two sentences, front-loading the purpose and then explaining key behavioral details (parallel PATCH, partial failure). No redundant words or repetition. Ideal conciseness for the complexity level.

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?

Given that there is no output schema, the description adequately covers the update mechanism and error response. It explains the optional nature of parameters (any subset can be provided) and partial failure handling. However, it could mention that this is for tailnet-level contacts, which is clear from context. Score 4 for covering essential behavioral aspects without major gaps.

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% with each parameter having a brief description (e.g., 'Account contact email'). The tool description adds that parameters are patched in parallel but does not elaborate on parameter syntax or constraints. Baseline is 3 due to high schema coverage, and the description provides marginal added value.

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 verb 'Update' and resource 'tailnet contact information', specifying the three contact types (account/support/security). It does not explicitly differentiate from the sibling 'tailscale_get_contacts', but the action is distinct enough. A score of 4 reflects good clarity without explicit sibling differentiation.

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 lacks any guidance on when to use this tool versus alternatives like 'tailscale_get_contacts' or 'tailscale_resend_contact_verification'. It describes the update behavior but does not provide context for selection, resulting in a score of 2 for missing when-to-use and when-not-to-use instructions.

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