Schedule a deep data-integrity scrub on a Ceph placement group to verify object consistency and detect silent corruption.
[WRITE][risk=medium] Schedule a deep (data-integrity) scrub on a PG.
Args: pgid: Placement group id, e.g. "2.1a" (from pg_summary / scrub_status). target: Ceph target name from config; omit for the default.
| Name | Required | Description | Default |
|---|---|---|---|
| pgid | Yes | ||
| target | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=true, and the description's [WRITE][risk=medium] tags are consistent with them. It adds that the scrub is a data-integrity operation, but says nothing about I/O load, expected duration, reversibility, or that the operation is asynchronous — all relevant for a non-idempotent mutation.
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?
Very compact: the risk/verb tags are front-loaded, followed by a one-line purpose and a two-item Args block where every line earns its place. No filler or repetition.
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?
No output schema exists, so the description could reasonably say what is returned (e.g., a task reference) and how to follow progress via scrub_status. It covers inputs and the write nature adequately but leaves the agent without guidance on monitoring or expected effect.
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%, so the description must carry the burden, and it does: it gives the pgid format with a concrete example ("2.1a") plus where to obtain it, and explains that target is a Ceph target name whose omission selects the default. This meaningfully exceeds the bare 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 (schedule) and resource (deep/data-integrity scrub on a PG), and the 'deep' qualifier implicitly separates it from the sibling trigger_scrub. It stops short of explicitly naming that sibling or stating the contrast, so it is clear but not fully self-differentiating.
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 [WRITE][risk=medium] tag and the note that pgid comes 'from pg_summary / scrub_status', which helps the agent source the input. There is no explicit when-to-use/when-not guidance, no mention of when to prefer a shallow scrub (trigger_scrub), and no prerequisites such as required permissions or cluster state.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.