osd_mark_in

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

Annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=true, so the safety profile is covered. The description adds value the annotations don't: a 'risk=medium' grading and the operational meaning of the mutation. It still omits what actually happens to data/PGs (backfill/recovery) and whether the change is reversible via osd_mark_out.

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 tight: a bracketed marker for operation type and risk, then a one-line semantic gloss, then a compact two-entry Args block. Front-loaded with the operation and risk, and nothing is wasted.

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?

For a 2-param write tool with annotations covering the safety profile and no output schema, the definition supplies what an agent needs: the write/risk marker, the semantic meaning, and documentation of both parameters. It could go further on side effects (recovery/backfill triggered, reversibility), which is the only meaningful remaining 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 description coverage is 0%, so the description must carry the burden — and it does document both params, noting osd_id is a numeric id sourced from osd_tree and that target can be omitted for the default. It adds the provenance of the id, which the bare schema does not. Minor gap: no format hints for target.

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+resource (mark an OSD 'in') and immediately glosses the semantics: 'return a drained/repaired OSD to service'. This makes the direction of the operation unambiguous. It does not explicitly name the sibling osd_mark_out, so it stops short of full sibling differentiation.

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 parenthetical '(return a drained/repaired OSD to service)' implies the appropriate context — you use this after a drain or repair — which is real usage guidance. However there is no explicit when-to-use vs osd_mark_out/osd_reweight routing, and no stated prerequisites or exclusions.

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