janitor_clean_caches

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

With no annotations, the description carries the full burden and does well: it discloses that dry_run defaults to true (safe, report-only), that older_than_hours gates EVERY removal, and names the concrete paths affected. It omits privilege requirements and whether deletion is reversible, which keeps it short of a 5.

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 compact clauses, front-loaded with the purpose, then targets, then the two behavioral gates. Every fragment carries information; nothing is repeated from structured fields for padding.

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?

An output schema exists, so return values need no explanation, and the description covers targets, the age gate, and the default dry-run behavior. It stops short of stating prerequisites or the relationship to sibling cleanup tools, but is otherwise sufficient for correct 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 coverage is 0% and the schema gives targets only as a free-form string array, so the description's enumeration (sockets, staging, testing_scratch) is the sole source of valid values. It also explains older_than_hours as a gating threshold and dry_run as report-only, fully covering all three parameters beyond the schema.

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?

States a specific verb (clean) plus resource (transient caches) and enumerates exactly which caches, making it trivially distinguishable from janitor_scan_orphans and janitor_sweep_processes. An agent knows immediately this is the cache-reclamation tool, not a scanner or process tool.

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?

Usage is implied by the enumeration of targets and the dry-run default, so an agent can infer this is the tool for reclaiming stale cache files. However, it never states when to prefer this over siblings, nor any prerequisite conditions (permissions, when caches are safe to remove).

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