market_coingecko_coin_market_chart

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

With no annotations provided, the description carries the full burden for behavioral disclosure, but it only states the basic data fields. It does not mention rate limits, response format, how 'days' and 'interval' interact, or whether data is returned as arrays of [timestamp, value] pairs. The behavior is simple, but the lack of any extra detail beyond the one-line purpose is insufficient.

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 that is concise and front-loaded. It minimally conveys the core function without repetition or fluff. However, it is slightly under-specified given the need to differentiate among many sibling tools, which costs it a perfect score.

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 has no output schema and no annotations, yet the description does not explain return values or data structure. With many similar market tools, the description lacks sufficient context to distinguish behavior (e.g., time range vs fixed range). The basic 'price, market cap, volume' phrase is helpful but incomplete for an agent to correctly select and 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 parameters (id, days, interval, vsCurrency) are already well-documented in the schema. The description adds no extra meaning beyond the schema, such as examples, defaults behavior, or relationships between parameters. This aligns with the baseline of 3.

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 specific verb ('Get') and identifies the resource as 'historical market chart data (price, market cap, volume) over time'. This clearly indicates what the tool returns and is distinct from related tools like market_coingecko_coin_history or market_coingecko_coin_ohlc, though it does not explicitly name alternatives or explain how this differs from market_coingecko_coin_market_chart_range.

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 similar siblings such as market_coingecko_coin_market_chart_range, market_coingecko_coin_ohlc, or market_get_coin_chart. There are no exclusions, prerequisites, or contextual hints about which tool fits a specific use case.

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