compaction_status

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

The annotations already declare readOnlyHint=true, and the description's 'Read' is consistent with that. The description adds genuinely useful behavioral nuance: 'completed requires a new completed contextCompaction event, not just an accepted request,' which prevents an agent from mistaking an accepted request for a completed one. It does not describe the return payload, but the annotations lower the burden for safety-related behavior.

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 two concise sentences with no filler. The core action is front-loaded, and the second sentence adds a compact, high-value behavioral caveat without restating schema or annotation facts.

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 one-parameter read-only tool with a readOnlyHint annotation, the description covers the purpose, the 'local' scope, and a key status-interpretation condition. It is sufficient for an agent to invoke correctly, though it could slightly improve by pointing to probe_compaction when a lighter check is needed or by outlining what the result contains.

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 single parameter, threadId, is already fully documented in the schema with explicit guidance to obtain it from the shell environment and never guess. The description itself does not add any parameter-specific meaning beyond what the schema provides, so it sits at the baseline for 100% schema coverage.

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 the local compaction job result.' This clearly communicates the tool's function and read-only nature. However, it does not explicitly distinguish itself from the sibling tool 'probe_compaction,' whose name could also imply checking compaction status.

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 main clause gives a clear activity, and the caveat about 'completed requires a new completed contextCompaction event' adds conditionality. However, it never explicitly says when to use this tool versus 'probe_compaction,' 'schedule_compaction,' or 'cancel_compaction,' nor does it state when not to use it. Usage context is implied rather than directly stated.

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