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

With no annotations provided, the description carries the burden of behavioral disclosure. It discloses the important partial-update behavior ('Any field not provided will remain unchanged'), which is valuable context. However, it does not mention side effects, idempotency, return value, or authorization requirements, leaving gaps expected for a mutation tool.

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 long, front-loaded with the core action, and every word earns its place. The partial-update clarification is concise and materially useful.

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 the tool's moderate complexity (8 params, nested objects, enums), the schema covers the parameter space well. The description adds the critical partial-update semantic, which is often omitted. No output schema exists, so return value explanation isn't required, but the description could still mention expected outcomes (e.g., success/failure behavior). Overall, it is sufficiently complete for a simple CRUD update 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?

Schema description coverage is 100%, so the schema already documents all parameters. The description does not add parameter-specific semantics beyond the generic partial-update note, which is already clear from the schema and overall description. Baseline 3 applies as the schema does the heavy lifting.

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 action ('Update') and the resource ('existing automation rule'), using a specific verb+resource construction. It distinguishes itself from sibling tools like create_automation_rule, delete_automation_rule, and get_automation_rule by explicitly focusing on updating an existing rule.

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 indicates this tool is for updating existing rules, which implies it should be used when a rule already exists, but it does not explicitly mention alternatives or exclusions (e.g., 'use create_automation_rule for new rules'). The partial-update behavior ('Any field not provided will remain unchanged') provides context on how to use it, but no explicit when-not-to-use guidance.

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