get_instances_by_status

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

No annotations are provided, so the description must disclose behavior. It explains the return value (list of instances) but does not mention pagination, error handling, or performance characteristics. For a simple filter, this is acceptable but minimal.

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 with only three sentences, yet it includes clear 'Args' and 'Returns' sections. Every word is purposeful, and the structure is well-organized, making it easy for an agent to parse quickly.

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 simplicity (one required parameter, no nested objects) and the presence of an output schema, the description covers the basic purpose. However, it lacks contextual cues about when to prefer this tool over similar ones, limiting completeness for an agent unfamiliar with the domain.

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 schema has 0% description coverage, so the description must add meaning. It lists example status values (ACTIVE, SHUTOFF, etc.) but does not specify if the list is exhaustive or provide format details. This adds some value but is insufficient for full parameter understanding.

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 retrieves instances filtered by status, with a specific verb and resource. It distinguishes from siblings like get_instance (single instance) but does not explicitly differentiate from search_instances, which may offer more flexible filtering.

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 provides no guidance on when to use this tool versus alternatives. There is no mention of when not to use it or comparison with similar tools like search_instances, leaving the agent to infer optimal usage.

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