historical_market_cap

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

With no annotations, the description carries full responsibility for behavioral disclosure. It only implies a read operation via 'Get' but does not disclose data source, return format, time coverage, or any limitations. This is a significant gap for a market data 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 a single sentence and is front-loaded with the action, containing no fluff. It is appropriately sized for a simple tool, though it could benefit from a bit more detail without becoming verbose.

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?

Without an output schema, the description should explain what data is returned (e.g., format, granularity, units). It also fails to disambiguate from many similar historical data tools. The minimal description leaves key gaps for an agent deciding to invoke this tool.

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 100%, so the baseline is 3. The description does not add any extra meaning beyond the schema; the parameter descriptions are minimal but present. No additional semantics such as units or supported symbol formats are provided.

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 uses a clear verb+resource construction: 'Get historical market cap data.' It accurately conveys what the tool does, but it does not differentiate from sibling tools like historical_ohlcv, historical_prices, or market_get_coin_chart, which may also provide historical market cap 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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any prerequisites, exclusions, or preferred use cases, leaving the agent to choose without additional context.

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