OPA capabilities

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

The description discloses what the tool returns and the three modes. It does not explicitly state read-only or side effects, but given no annotations, it adequately conveys the tool's behavior for a capabilities inspection function.

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 a single sentence, front-loaded with the core purpose, and structured cleanly to enumerate the three modes. No wasted words.

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?

Given the tool's simplicity (two optional parameters, no output schema), the description is complete. It covers all usage scenarios and return value content without missing information.

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 baseline is 3. The description adds significant value by explaining the behavioral difference between providing current, version, or neither, which is not fully captured in parameter descriptions.

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 the tool returns OPA capabilities (builtins, keywords, features, WASM ABI versions) and distinguishes three modes of operation: current, specific version, or listing versions. This is a specific verb+resource combination.

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 description explicitly explains when to use each parameter: current for running OPA, version for a specific version, neither for listing versions. It provides clear context but does not mention when not to use or alternatives, though sibling tools are distinct.

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