list_server_groups

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds value beyond that by describing what comes back (instance counts, cloud provider details, region info) and confirming this is an unfiltered listing of all server groups for the app.

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?

Three tight sentences, zero redundancy: purpose first, then usage, then return shape. Every clause carries information and the most important routing fact (what is listed and for whom) is front-loaded.

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 no output schema, the description correctly carries the return contract (JSON array of server group objects with instance counts, provider and region info), which is what an agent needs. The remaining minor gap is that pagination/volume expectations and sibling routing are not mentioned, but for a simple one-argument read tool the coverage is largely adequate.

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?

There is only one parameter and schema description coverage is 100%, so the schema already fully documents 'application' as the registered Spinnaker app name. The description adds a small reinforcing hint ('for a Spinnaker application') but no format, casing, or validation detail beyond the schema; baseline 3 applies.

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?

Starts with a specific verb+resource ('List all server groups') and immediately disambiguates the resource by naming cloud-specific equivalents (ASGs, instance groups, replica sets). The scoping phrase 'for a Spinnaker application' tells an agent exactly what universe the listing covers, distinguishing it from get_target_server_group and get_cluster.

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 sentence 'Use this to view active deployment targets and their instance counts across regions and accounts' gives a concrete use case and the axes it spans. It stops short of naming alternatives or stating when NOT to use it (e.g., versus get_target_server_group for a single group), so no explicit routing is provided.

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