capacity_runway

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

No annotations are provided, so the description carries the full burden. It discloses deterministic behavior ('No clock or randomness — same inputs, same answer') and the outcome when 'daily_growth_bytes' is omitted. This is sufficient for a simple read operation.

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 with a clear structure: a brief summary line, followed by a paragraph explaining behavior, and a 'Args:' list. Every sentence adds value, no redundancy. The [READ] tag at the beginning is helpful.

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 description covers inputs and behavior well, but lacks details about the return value format (e.g., what does the output look like? Is it a number, a string?). Since there is no output schema, the description should clarify what the tool returns. This is a minor gap.

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 coverage is 0%, so the description must compensate. It explains each parameter: 'cluster_ext_id: Cluster extId as returned by cluster_list', 'daily_growth_bytes: Assumed daily storage growth in bytes (omit to skip forecast)', and 'target: Prism Central target name from config; omit for the default.' This adds significant meaning beyond the schema's basic titles.

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's purpose: 'Deterministic storage-runway estimate for a cluster (days-to-full).' It uses a specific verb ('estimate') and resource ('storage-runway'), and clearly distinguishes from sibling tools which are mostly cluster management, snapshots, etc. No ambiguity.

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 explains when to supply the 'daily_growth_bytes' parameter ('Supply daily_growth_bytes... to project daysToFull') and the consequence of omitting it ('forecast is 'insufficient-data''). It also notes that 'target' is optional. While it doesn't explicitly list when not to use or alternatives, the context is clear and the tool is distinct from siblings.

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