Mutmut MCP

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

With no annotations, the description carries full burden but provides limited behavioral insight. It mentions the output format ('plain text output'), which is helpful, but lacks details on permissions, side effects, error conditions, or rate limits. For a tool that likely reads mutation test results, more context on what 'surviving mutations' means operationally would improve transparency.

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 concise and front-loaded, stating the core purpose in the first sentence. The second sentence adds useful output format detail without redundancy. It avoids fluff, but could be slightly more structured (e.g., by explicitly mentioning the parameter).

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 moderate complexity (CLI-based, mutation testing context), no annotations, and an output schema, the description is minimally adequate. It covers the basic action and output format, but lacks details on prerequisites (e.g., requires a prior mutmut run), parameter use, or how it integrates with siblings. The output schema helps, but more operational context 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?

Schema description coverage is 0%, so the description must compensate, but it adds no parameter information. The single parameter 'venv_path' is undocumented in both schema and description. However, with only one optional parameter and an output schema present, the baseline is moderate. The description doesn't explain what 'venv_path' is or when to use it, leaving a gap.

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 action ('List details') and resource ('surviving mutations from the last mutmut run'), and specifies the tool uses the mutmut CLI. It distinguishes from siblings like 'show_results' or 'show_mutant' by focusing specifically on survivors. However, it doesn't explicitly contrast with all siblings, preventing a perfect score.

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 minimal usage guidance. It implies this should be used after a mutmut run to see survivors, but offers no explicit when-to-use rules, prerequisites, or alternatives. For example, it doesn't clarify when to use this versus 'show_results' or 'prioritize_survivors', leaving the agent to infer context.

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