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

With no annotations, the description carries the full burden and does reasonably well: it explicitly discloses that no API call is made and no credits are consumed, and it enumerates what each topic contains (error code tables, retry strategy, rate-limit behavior). It stops short of stating read-only/side-effect semantics explicitly, but the 'no API call' phrasing covers most of that ground.

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 most important fact (reference docs, no cost), then a tight bulleted list where each bullet earns its place by previewing the topic's contents. No filler, though the bullet for each action could be trimmed slightly.

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 and no annotations, the description must describe the return content, and it does so per action. It is complete enough to invoke correctly; the only gap is the absence of any signal about how this differs from sibling system_info tools.

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 the baseline would be 3, but the description adds real meaning beyond the bare enum labels by explaining what each action returns (e.g. 'credits — Credit charging structure, cost multipliers... monitoring & operations taxes'). The optional 'context' parameter is left to the schema, which documents it adequately.

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 verb and resource: retrieve CryptoAPIs reference documentation topics, with a clear scope ('no API call, no credits consumed'). However, it does not differentiate this instance from the roughly fifteen sibling system_info tools (address_history, aml, blockchain_fees, etc.), which likely expose the same or overlapping topics.

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?

It gives useful context ('no API call, no credits consumed') that signals a safe, free lookup, but never states when to prefer this system_info over a sibling namespace's system_info, nor any exclusions. Usage is implied by the action list rather than explained.

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