list_instances

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

With no annotations, the description carries the burden and discloses key behavior: default returns a trimmed summary, and raw=true returns full OCI SDK objects. This adds meaningful context beyond the schema, though it omits other details like pagination or permissions.

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-loaded with the primary purpose, and every word earns its place. No fluff or redundant information.

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 list tool with four optional parameters and no output schema, the description sufficiently explains the operation and return format (trimmed vs raw). It is slightly vague about exactly what the trimmed summary contains, but overall complete enough for typical use.

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 baseline is 3. The description only references the 'raw' parameter and does not add new meaning to other parameters beyond what the schema already provides.

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 lists Compute instances in a compartment, specifying both the resource type and scope. It distinguishes itself from sibling tools like get_instance (single instance) and instance_action (actions) by the verb 'Lists' and resource focus.

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 implies usage as a list operation but does not explicitly state when to use it over alternatives like get_instance or list_vcns. No exclusions or alternative tool references are provided, leaving the context partially implied.

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