rc_error

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

The description discloses key behavior: it always returns an error response and incorporates supplied parameters. Since no annotations are provided, the description carries the full burden and does so adequately, though it could mention the _async parameter's effect on the response.

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, front-loaded sentence that conveys all essential information without any fluff. Every word serves a purpose, making it highly efficient.

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?

While the description covers the core purpose and behavior, it omits details about the _async parameter's impact (e.g., if async is true, the tool may return a job id rather than an immediate error). Additionally, without an output schema, more information about the error response format would improve completeness.

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?

Both parameters are fully described in the input schema (100% coverage), so the description adds little additional meaning beyond 'incorporating the supplied parameters'. The description does not explain each parameter's role beyond what the schema already provides, so a baseline score of 3 is appropriate.

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 'Return a test error' and 'Always returns an error response', which precisely defines the tool's purpose. It distinguishes itself from sibling test tools like rc_noop and rc_noop_auth by specifying it returns an error, making it unambiguous.

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 mentions it is 'useful for testing error handling', providing clear context for when to use the tool. However, it does not explicitly exclude other test tools or provide guidelines on when not to use it, which would earn a 5.

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