One instance in detail

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds the return format (JSON with {ok, message, next_tool, next_args, ...tool-specific fields}) and the specific data fields, which is useful. However, it does not disclose behavior like whether the instance must exist, error handling, or rate limits. With annotations covering safety, a 3 is appropriate.

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 concise and front-loaded with the key fields returned. The return format is mentioned in the second sentence, which is useful. It is appropriately sized for a simple read tool, though it could be slightly more structured by separating the return format from the field list.

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?

The tool has an output schema, so return values are partially covered. However, the input schema has 0% description coverage, and the description does not explain the 'template' parameter or any prerequisites. For a read-only tool with annotations covering safety, the description is adequate but not complete. The missing parameter semantics and lack of usage guidance leave 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 0%, so the description must compensate for the undocumented parameters. The description mentions 'a single instance' but does not explain the 'instance_id' parameter or the optional 'template' parameter. The schema only provides types and required status, leaving the agent to infer the meaning of 'template'. This is a significant gap.

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 states a specific verb ('get') and resource ('a single instance') and lists the concrete fields returned (status, endpoint, SSH command, spend, teardown schedule). It is clear what the tool does, though it does not explicitly distinguish itself from sibling tools like list_instances or wait_for_instance.

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 for retrieving detailed information about one instance, but it does not explicitly state when to use this tool versus alternatives like list_instances or wait_for_instance. The context signals and sibling list provide some context, but the description itself lacks explicit when-to-use or 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.