direct_reference

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

There are no annotations, so the description carries the burden of behavioral disclosure. It does this well by listing the informational content and framing the tool as a read-only reference/cheat sheet. It does not explicitly state that it has no side effects or describe the return format, but the reference framing makes the behavior sufficiently clear.

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 sentences with no wasted words: the first front-loads what the tool provides, and the second gives the actionable trigger. Every phrase earns its place.

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 zero-parameter reference tool, this is complete: it specifies the domain (API v5), the exact reference content, and when to call it. The lack of an output schema is mitigated by the explicit enumeration of what the cheat sheet covers.

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?

The input schema is empty with zero parameters, so the baseline is 4. The description does not discuss this tool's parameters, but it uses the word 'params' only in the context of examples for direct_call, avoiding confusion. No additional parameter explanation is needed.

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 identifies the tool as a 'cheat sheet' for API v5 and enumerates its contents: services, methods, params examples, report types, rate units, and limits. This clearly distinguishes it from sibling execution tools like direct_call and direct_report, so an agent knows exactly what this reference operation is for.

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 an explicit when-to-use instruction: call this before the first direct_call to avoid guessing fields. This is clear context, but it does not mention when not to use it or contrast it with direct_status/direct_report, so it stops short of a full 5.

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