get_capacity_overview

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is established. The description adds meaningful behavioral detail beyond annotations: it notes that values are None while capacity analytics are warming up on a fresh instance, and it identifies the data source (OnlineCapacityAnalytics metrics). This is useful non-obvious context.

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 appropriately sized for the tool's complexity and front-loads the core action and outputs in the first sentence. The caveat about warming up and the sibling routing guidance each earn their place. No filler or repetitive content is present.

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?

There is no output schema, so the description carries the burden of explaining return semantics. It covers the key values (capacity_remaining_pct, per-dimension absolute remaining, days-until-full), the warm-up None behavior, and the data source. Given the simplicity of the input parameters and the annotations, the description is complete enough for correct selection and invocation.

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%, and both parameters already have descriptions: cluster_id is 'The cluster resource UUID (ClusterComputeResource, from list_resources)' and target has a default and config-origin note. The description adds little parameter-level meaning beyond the schema, so the baseline of 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?

The description states a specific verb ('Returns a capacity overview') and resource ('a cluster'), and precisely identifies the output components: group-level capacity_remaining_pct, per-dimension absolute remaining capacity, and projected days-until-full. It further distinguishes itself from sibling tools by naming what it includes and where it comes from, so an agent can clearly tell it apart from get_remaining_capacity and get_time_remaining.

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 explicitly says 'Start here when assessing overall cluster capacity health' and provides concrete alternatives for more focused needs: 'for absolute headroom values use get_remaining_capacity, and for just the exhaustion projections use get_time_remaining.' This gives the agent an unambiguous routing rule for when to use this tool versus its siblings.

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