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

Annotations only declare readOnlyHint=true, and the description adds real behavioral context: the data sources per venue, the default/max lookback window, and the important caveat that coin and time are parsed from notice text and 'a notice that does not name them says so.' It stops short of describing response shape or coverage gaps per venue beyond 'announcements when configured.'

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?

Front-loaded with the core purpose and scoping, then filters. It is dense and somewhat run-on in the middle (venue parentheticals), but nearly every clause carries information an agent needs; little is wasted.

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 an output schema present, return values need not be explained, and the description covers sources, time window, filter semantics, and parsing caveats. Nothing an agent needs to invoke this correctly is missing.

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 already 100%, so the baseline is 3, but the description adds meaning beyond the schema: it enumerates what 'all' actually includes (pair removals, margin/collateral changes, migrations, postponements) and clarifies comma-separated symbol usage. This is genuine added value over the enum labels.

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 verb+resource ('Exchange listings and delistings from the venues' own notices') and immediately scopes it to scheduled vs. recent events. It names the exact venues covered (Binance, Bybit, OKX, Upbit), which distinguishes it from generic siblings like catalysts_calendar or news_search.

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 context for when this matters ('delistings announced 2–7 days ahead; new listings... among the most price-moving events') and explains the filter dimensions. It does not explicitly name an alternative sibling tool or state when NOT to use it, so it falls short of a 5.

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