probe_compaction

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

The description aligns with the readOnlyHint=true annotation by explicitly stating 'Read-only', and adds the context that it verifies access to owner and runtime state. It does not describe return behavior, error conditions, or what happens if access is denied, but given the annotation already signals safety, the additional context is modest but adequate.

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 a single, front-loaded sentence that immediately communicates the read-only nature and primary purpose. It contains no filler or redundancy. While it is terse, it is appropriately sized for a simple tool.

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 tool with one required parameter, no output schema, and strong annotations, the description covers the basic operation but leaves open important context: how results are reported, why this probe is needed relative to compaction, and what 'owner and runtime state' concretely means. An agent could call it correctly but might not fully understand the expected outcome.

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 100% for the single threadId parameter, and the schema already provides the critical instruction to obtain it from the shell environment and never guess. The tool description adds no further parameter semantics, so the baseline score of 3 applies.

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 ('verify') and a specific resource ('owner and runtime state of the specified current Codex VS Code chat'). It clearly distinguishes itself from the sibling compaction tools by positioning this as a read-only verification action rather than status lookup, scheduling, or cancellation. However, 'owner and runtime state' is somewhat vague and could be clearer about what is being probed.

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 description provides no explicit guidance on when to use this tool versus the sibling tools (compaction_status, schedule_compaction, cancel_compaction). It implies a read-only verification role but does not state conditions, prerequisites, or alternatives. The agent must infer the intended usage context from the name and siblings alone.

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