JSON-RPC

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions this is for 'discovery' and part of the OpenRPC Specification, but doesn't describe what the tool actually returns (method list format), error conditions, authentication requirements, rate limits, or other behavioral traits. The description is insufficient for a tool with no annotation coverage.

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 appropriately concise with two sentences. The first explains the technical implementation, and the second provides a user prompt example. Both sentences earn their place by providing different types of information. It could be slightly more front-loaded with the primary purpose.

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 no annotations, no output schema, and 0% schema description coverage, the description is incomplete. It doesn't explain what the tool returns (critical for a discovery tool), doesn't cover error cases, and provides minimal parameter guidance. For a tool that presumably returns method information, the lack of output description is a significant gap.

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 description coverage is 0%, so the description must compensate. While it mentions the 'server url' parameter in the example prompt, it doesn't explain what format the server URL should be, whether it needs authentication credentials, or any constraints. The description adds minimal value beyond what the bare schema provides.

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 the tool 'uses JSON-RPC to call `rpc.discover`' which indicates it performs discovery for JSON-RPC servers. However, it's somewhat vague about what 'discovery' entails (listing available methods) and doesn't explicitly differentiate from the sibling tool 'rpc_call' beyond mentioning the specific RPC method name.

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 provides clear context for when to use this tool: when a user wants to know 'What JSON-RPC methods does this server have?' and includes the required server URL parameter. It doesn't explicitly state when NOT to use it or mention the alternative 'rpc_call' tool, but the example prompt gives good usage guidance.

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