knowl_gc_preview

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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'without changing the database.' It also discloses a subtle behavioral trait: the returned purgeItemIds are the IDs that knowl_gc_apply will not delete unless they are handed back. This adds real context beyond the annotation and is important for correct invocation.

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 tight sentences with no filler. The core purpose is front-loaded, the usage scenario follows, and the return-value caveat is placed at the end. Every sentence earns its place.

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 zero-parameter, no-output-schema tool, the description is complete: it explains what the tool does, why an agent would use it, that it is non-destructive, and what the single return field means. The reference to knowl_gc_apply's behavior also fills a critical operational 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?

The tool has zero parameters, and the schema description coverage is 100%, so there is no parameter information missing. The description adds no parameter-specific meaning, but none is needed. The baseline of 4 for zero-parameter tools 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 and resource: 'Preview knowledge garbage collection recommendations' without changing the database. It also distinguishes itself from knowl_gc_apply by explaining that the returned IDs are the ones knowl_gc_apply 'will not delete unless they are handed back to it.' The purpose is unambiguous.

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 explicitly says 'Use to find duplicate, stale, or cold memory before applying GC,' which gives a clear when-to-use context. It references knowl_gc_apply as the follow-up action, though it does not spell out an explicit 'when not to use' or compare against non-GC sibling tools.

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