list_all_key_usages

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

With no annotations provided, the description must carry the behavioral disclosure burden. It adds useful context: the call does not require AWS credentials, which is important operational information, and it describes what is returned. It does not mention pagination or potential rate limits, but for a zero-parameter list operation this is adequate.

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 description is three short sentences, each with clear value: when to use the tool, the credential requirement, and the return content. Usage guidance is front-loaded and no filler is present.

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 tool with an output schema, the description covers all essential facets: appropriate invocation scenarios, credential requirements, and the nature of the returned data. An agent has enough information to select and call this tool correctly.

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 tool has zero parameters, so the rubric baseline is 4. The description correctly adds no parameter-specific details because there are none to explain.

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 clearly states a specific verb and resource: list all TR-31 key usage codes with names, descriptions, and APC support status. This is a directory-style lookup, which sets it apart from sibling tools that create, modify, or explain individual keys.

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 provides explicit contexts for when to call it: designing key infrastructure, selecting key types for payment operations, or answering questions about APC-supported key types. However, it does not name alternatives or explicitly state when not to use it, so it falls short of a perfect 5.

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