Get Cache & Query Metrics

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

Annotations already declare the tool as read-only, idempotent, and non-destructive, so the description doesn't need to repeat that. It adds value by enumerating the specific metrics returned, but doesn't disclose other behavioral traits like time windows, aggregation scope, or output format. This is acceptable given the annotation coverage.

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 sentence with no filler words. It front-loads the action and immediately enumerates the queried metrics, earning every word.

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 parameterless metrics-retrieval tool, the description is reasonably complete: it names all three metric categories returned. Without an output schema, it still conveys what the caller will receive, though it omits edge cases like empty results or units.

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, so the schema fully covers parameter semantics (trivially). The description adds no parameter-specific information because there is nothing to add. Baseline for zero-parameter tools is 4.

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 clearly states the tool queries specific metrics: cache-hit ratio, average visual similarity scores, and token-savings estimates. It uses a specific verb ('query') and resource ('metrics'), and though it doesn't explicitly distinguish from siblings, the content makes its purpose clear.

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?

No information is provided about when to use this tool versus alternatives. There are no usage scenarios, prerequisites, or exclusions, leaving the agent to infer appropriateness from the metric names alone.

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