hcloud_list_scaling_instances

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds only the word "currently", implying active instances, but says nothing about pagination, empty results, or whether terminated/removed members are excluded.

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?

A single front-loaded sentence with no filler. It is efficient, though the unexplained "AS" abbreviation slightly under-specifies rather than wastes space.

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?

With two required parameters, no output schema, and annotations covering read-only semantics, the definition is minimally adequate. It would be stronger if it clarified that results are scoped to one scaling group and hinted at what instance fields are returned.

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 region and scaling_group_id are already documented with required status. The description adds no format, ID syntax, or scoping detail beyond what the schema states, making the baseline 3 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?

"List instances currently in AS groups" gives a specific verb (list) and resource (instances inside auto-scaling groups), which distinguishes it from hcloud_list_scaling_groups and hcloud_show_scaling_group. The only weakness is the unexplained abbreviation "AS", which assumes the agent knows it means Auto Scaling.

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?

There is no guidance on when to call this versus hcloud_list_scaling_groups, hcloud_show_scaling_group, or hcloud_list_scaling_configs, and no prerequisites or exclusions are stated. The agent must infer usage purely from the name.

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