Code MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('create') but doesn't cover critical traits: whether it requires specific permissions, what happens on conflicts (e.g., if the directory already exists), if it's idempotent, or the response format. This is a significant gap for a mutation tool with zero 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 a single, efficient sentence with zero waste—'Create a new directory' is front-loaded and directly conveys the core purpose. Every word earns its place, making it easy for an agent to parse quickly without unnecessary elaboration.

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 complexity (a mutation tool with no annotations and no output schema), the description is incomplete. It lacks behavioral context (e.g., error handling, permissions), usage guidelines, and output details. While the schema covers the parameter, the overall context for safe and effective tool invocation is insufficient.

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 schema description coverage is 100%, with the 'path' parameter fully documented in the schema. The description doesn't add any meaning beyond this (e.g., path format, relative vs. absolute). According to the rules, when schema coverage is high (>80%), the baseline is 3 even with no param info in the description, which applies here.

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 'Create a new directory' clearly states the action (create) and resource (directory), making the purpose immediately understandable. It distinguishes from siblings like 'list_directory' (read) and 'delete_file' (remove). However, it doesn't specify the scope or context (e.g., filesystem, workspace), which prevents 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?

No guidance is provided on when to use this tool versus alternatives. The description doesn't mention prerequisites (e.g., permissions, existing parent directories), exclusions (e.g., what happens if the path exists), or related tools like 'create_project' for broader workspace setup. This leaves the agent without context for decision-making.

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