instance_action

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

With no annotations provided, the description must carry the burden of disclosing behavioral traits. It does state that the tool is blocked when OCI_READ_ONLY=true, signaling that it is a write operation and that read-only mode prevents execution. However, it does not mention other important behaviors such as whether actions are asynchronous, what response to expect (no output schema), potential state preconditions (e.g., instance must be stopped before starting), or reversibility of actions.

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 extremely concise: two sentences, front-loaded with the primary purpose and then a critical constraint. Every word earns its place, with no filler or repetition of schema details. Excellent structure.

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 mutating tool with no annotations and no output schema, the description provides essential purpose and one key constraint, but omits other contextual information that would help an agent, such as whether operations take effect immediately, how to verify success (e.g., using get_instance), or error conditions. It is adequate but not rich enough for a lifecycle-management 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?

The input schema already provides 100% coverage for all three parameters (action, region, instanceId), including an enum-like list for action and a default for region. The description's mention of 'lifecycle action' adds minimal extra meaning beyond the schema, but it does reinforce the purpose of the action parameter. Since the schema carries the heavy lifting, a baseline of 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's function with a specific verb ('Performs'), a precise resource ('Compute instance'), and an enumerated list of lifecycle actions (START, STOP, etc.). This unambiguously distinguishes it from sibling tools that are primarily read-only list/get operations.

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 makes the intended use case obvious: performing lifecycle actions on Compute instances. It does not explicitly compare against alternatives, but the sibling context shows a clear separation from read-only/list tools, so an agent can infer when to select this tool. The OCI_READ_ONLY constraint adds a clear condition under which the tool should not be used.

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