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

Annotations only provide readOnlyHint=true; the description adds substantial behavioral detail: cross-exchange aggregation, a single-venue fallback when the aggregate source is offline, series low/high context, and the ability to suppress the series. This is exactly the kind of beyond-annotation transparency the dimension asks for.

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 most important result summary is front-loaded, followed by interpretation, fallback, and parameter guidance. It is longer than average, but each sentence carries operational value; the only slight excess is the interpretive trading guidance, which is still relevant to selecting and using the tool.

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?

With no output schema, the description compensates by enumerating the main returned components: current OI, changes, price change, 4h series, series low/high, and fallback behavior. It also explains the points parameter's effect on output shape, so an agent has enough to call the 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?

Schema description coverage is 100%, so the schema already documents symbol and points thoroughly. The description reinforces the points behavior (trim, omit, or suppress) and ties symbol to 'one coin', but does not add materially new parameter semantics beyond that baseline.

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?

States a specific deliverable: current market-wide cross-exchange aggregate open interest in USD for one coin's perpetuals, plus 24h/7d changes, 24h price change, and a 4h series. This clearly distinguishes it from siblings like funding_current or market_candles, and it even references market_candles as a companion for the price leg.

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?

Gives clear analytical context: read OI against price, use the 4h series bucket-by-bucket, and pair with market_candles at 4h for the price leg. It does not explicitly list when not to use this tool versus other derivatives-related siblings, so it misses the top bar.

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