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

With no annotations, the description carries the full burden. It usefully discloses an authentication requirement ('Requires compactions:run for API keys'), which is genuine added context. However it says nothing about whether the estimate is a pure read, whether it has side effects, rate limits, or the shape of the returned cost value.

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?

Two tight sentences with the action and cost subject front-loaded, and the permission requirement appended as a secondary detail. No filler.

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?

Auth is covered and there is no output schema to explain, but for a 2-parameter tool at 0% schema coverage the description omits what each identifier means and what the returned estimate looks like, leaving clear gaps an agent must guess at.

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% and the description documents neither parameter. 'of one file' loosely implies a file identifier, but artifactBundleId is entirely unexplained and no format/relationship between the two UUIDs is given, so the description fails to compensate for the coverage gap.

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 (Estimate) plus the exact resource and scope (credit cost of a deep compaction of one file), and the phrase 'before starting it' implicitly contrasts with the sibling rubrkit_apply_deep_compaction. An agent can distinguish this pre-flight estimator from the actual apply tool without opening either schema.

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?

'before starting it' gives an implied timing cue for when to call the tool, but no alternative sibling is named and there are no exclusions or conditions spelled out. The usage context is inferable rather than explicit.

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