compaction_status

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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'Read-only'. It adds substantial behavioral context beyond annotations: intermediate status semantics, 'completed requires a newly observed completed contextCompaction event', 'resumed identifies a returned continuation turn, not successful work', and the telemetry-staleness caveat about insufficient_headroom. No contradiction detected.

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?

Every sentence earns its place: the tool's nature, the usage timing, the status semantics, and the telemetry caveat. The most important usage guidance is front-loaded, and there is no filler or repetition of schema content.

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?

Given the tool's moderate complexity and lack of output schema, the description is complete: it explains when to call it, what it inspects, how to interpret statuses, and a critical failure mode. An agent has enough information to invoke it correctly and interpret its results in context.

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?

The only parameter, threadId, is fully documented in the schema with clear instructions about obtaining it from CODEX_THREAD_ID and not guessing. The description adds no parameter-specific meaning, but since schema coverage is 100%, the baseline of 3 is appropriate.

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 states a specific verb and resource ('Read-only local job inspection') and clearly distinguishes itself from siblings by naming them and noting what it does not do ('does not probe extension compatibility'). An agent can tell this tool from probe_compaction and schedule_compaction without inspecting schemas.

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?

It explicitly names when to use the tool: before probe_compaction or schedule_compaction to detect an unfinished job, and after scheduling or cancellation to inspect outcome and metrics. It also names the sibling alternatives and an exclusion, making selection unambiguous.

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