list_cached_symbols

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

No annotations are provided, so the description carries the full burden. It discloses the local SQLite cache as the data source and explicitly provides the return JSON format, which is beyond what the empty input schema offers. Although it does not explicitly state that the operation is read-only, 'List' and 'cache' imply non-destructive behavior. This is sufficient for a simple listing tool.

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 sentences: the first states purpose, the second gives the return type. Every word adds value and it is front-loaded. No extraneous information or repetition.

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?

The tool is simple: no parameters, no output schema, and the description covers both what it does and the exact return structure. The mention of 'local SQLite cache' and the return format fully equips an agent to invoke and interpret the result. There is no missing critical context.

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 is trivially 100% covered. According to the rubric, 0 parameters yields a baseline of 4. The description adds no parameter details (there are none), so no additional credit or penalty is applied.

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's function: 'List stock symbols that already have OHLCV data in the local SQLite cache.' It uses a specific verb ('List'), identifies the resource ('stock symbols'), and includes a distinguishing qualifier ('already have OHLCV data in the local SQLite cache') that separates it from sibling tools like get_stock_data.

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 implicitly conveys when to use the tool: to check which symbols already have cached OHLCV data. However, it does not explicitly mention alternatives or when not to use it, so it lacks the explicit exclusion/alternative guidance required for a 5. The context is clear, earning a 4.

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