Mutmut MCP

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

With no annotations, the description carries the full burden of behavioral disclosure. It states the tool returns 'plain text output,' which is helpful, but lacks details on prerequisites (e.g., requires a prior mutmut run), error handling, or performance traits. It doesn't contradict annotations, but provides only basic operational context.

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 extremely concise and front-loaded, consisting of two clear sentences that directly state the tool's function and output format without any wasted words. Every sentence earns its place by providing essential information efficiently.

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 low complexity (one optional parameter) and the presence of an output schema (which likely covers return values), the description is moderately complete. It explains what the tool does and the output format, but gaps remain in parameter guidance and behavioral context, making it adequate but with clear room for improvement.

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 description provides no information about the 'venv_path' parameter, which has 0% schema description coverage. This leaves the parameter's purpose and usage undocumented, failing to compensate for the schema gap. The baseline would be higher if parameters were absent, but here the description adds no value beyond the schema.

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's purpose: 'Display overall results from the last mutmut run using the mutmut CLI.' It specifies the verb ('Display'), resource ('overall results'), and context ('last mutmut run'), though it doesn't explicitly differentiate from siblings like 'show_mutant' or 'show_survivors' which likely show specific subsets of results.

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 guidance, implying usage after a mutmut run to view results, but offers no explicit when-to-use rules, exclusions, or alternatives. It doesn't clarify if this should be used instead of or alongside siblings like 'show_survivors' for different result types.

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