cache_status

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

Annotations already indicate read-only and idempotent, but the description adds valuable context beyond that: the multi-user mode nuance (returns authenticated user's plan), the fact that it performs a multi-GB row-count scan, and the explicit offload to a worker thread to avoid blocking the event loop. These are meaningful behavioral disclosures not present in annotations.

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 efficiently structured: the first sentence states the core purpose, followed by exclusion/alternative guidance, then a context nuance, and finally an implementation detail. Each sentence earns its place without redundancy. While longer than average, it is front-loaded and every sentence adds unique value.

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?

Given zero parameters, an output schema, and rich sibling context, the description is complete. It covers return content (metadata), exclusions, alternative tools, multi-user behavior, and performance characteristics. No important context is missing for an agent to select and invoke this tool correctly.

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 there is no parameter semantics to explain. Per the rubric, 0 params baseline is 4. The description doesn't need to add parameter meaning, and it correctly focuses on what the tool returns and how it behaves.

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 opens with a specific verb+resource: 'Show database metadata: table row counts, file size, and detected plan.' It clearly distinguishes itself from sibling detection tools by explicitly stating it does NOT query screener signals and lists alternative tools for that purpose. This is a model of purpose clarity.

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 gives explicit when-to-use context (cache metadata) and when-not-to-use context ('Do not call this tool to look up market data or screener results'). It names specific sibling tools for alternative detection tasks (detect_52w_high_low, detect_ytd_high_low, etc.), fulfilling the alternatives requirement perfectly.

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