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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds genuinely useful context beyond them: free tier with a daily per-caller quota, and the fact that payment credentials must travel in MCP request headers (X-Payment / X-Payment-Tx / Bearer fg_…) rather than parameters. That auth/quota disclosure is exactly the kind of behavioral detail that prevents failed calls.

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 lead sentence is well front-loaded, but the definition then repeats the same content in a [zh] and an [en] block, restating the free tier and the 'Args: exchange' line. Bilingual support is reasonable, yet the redundancy and the mixed-language asset title add noise an agent must parse.

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?

For a one-optional-parameter, read-only, no-output-schema tool, the definition covers the essentials: which exchanges, what data comes back, quota limits, and how payment is supplied. Only the optionality and accepted format of 'exchange' remain 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 0% for the single 'exchange' parameter, so the description must carry the meaning. It names the parameter and enumerates the five exchanges covered, which effectively defines the value domain, but it never states whether the parameter is optional, whether omitting it returns all five, or the exact string format to pass.

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 concrete verb+resource and what it returns: '5 exchanges up or down plus maintenance notice count' over OKX/Binance/KuCoin/Bybit/Gate. That is far more specific than the name alone. It does not explicitly distinguish itself from the sibling 'exchange-status.status', so it falls short of a 5.

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?

The framing question 'are the exchanges up right now' implies when the tool is appropriate, and the free-tier note hints at a lightweight pre-check use case. However, it never says when not to use it, nor routes the agent to a sibling such as exchange-status.status for per-exchange detail.

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