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

Annotations already declare readOnly, idempotent, non-destructive, and open-world behavior, so safety is covered. The description adds the return shape (per-exchange open interest in USD plus 24h change), which is genuine added context, but it omits any detail on rate limits, auth failures, or coverage of exchanges.

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?

Two front-loaded sentences convey purpose and return, with no filler. The appended example duplicates the invocation examples already present in the input schema, costing a little space without adding new information.

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 appropriately carries the return-value burden by describing per-exchange USD open interest plus 24h change. Annotations cover the safety profile, so the definition is nearly complete; only exchange coverage and error behavior are unstated.

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 coverage is 100%, so symbol, _apiKey, and the optional exchange filter are already fully documented. The description restates 'for a coin symbol' and implies exchange filtering but adds no syntax or edge-case meaning beyond the schema; the phrase 'across exchanges' even slightly undercuts the single-exchange filter. Baseline 3 applies.

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 states a specific resource (open interest) and scope (per-exchange, perpetual futures, USD plus 24h change), which clearly separates it from the sibling funding-rate, liquidations, and long/short-ratio tools by subject matter. It does not, however, explicitly name those siblings to help the agent disambiguate.

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?

There is no statement of when to use this tool versus coinglass_funding_rate, coinglass_liquidations, or coinglass_long_short_ratio. The only usage hint is a sample invocation, which teaches syntax rather than tool selection.

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