pbs_prune

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

Adds important behavioral context beyond the destructiveHint annotation by explaining that on-disk chunks are not freed until the next garbage collection. It also discloses environment requirements and the confirm flag, supplementing the annotation without contradiction.

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 three concise sentences, each providing distinct value: the main action, the GC consequence, and the usage prerequisite. No redundant or filler wording.

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 the essential safety context for a destructive tool: dry-run prerequisite, confirm requirement, and deferred space reclamation. While it does not detail all retention parameters, that gap is more about parameter semantics than overall completeness, and the presence of an output schema reduces the need to explain return values.

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 0% (per signals), and the description does not compensate by explaining the keep_* parameters or the role of each retention option. It only mentions confirm as a requirement and 'retention policy' generically, leaving most parameters under-documented.

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 applies a retention policy and drops matching snapshots, using specific verbs and resources. It distinguishes itself from pbs_prune_dry_run and other snapshot tools by indicating the actual deletion action.

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 instruction to always run pbs_prune_dry_run first provides a clear alternative and usage sequence. It also lists required prerequisites (PBS_ALLOW_WRITE=true and confirm=true), though it does not mention other alternatives like pbs_forget_snapshot.

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