Cozi MCP Server

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

No annotations are provided, so the description carries the full burden. It states the tool creates a list but doesn't disclose behavioral traits such as whether it requires specific permissions, what happens on success/failure, if it's idempotent, or any rate limits. For a mutation tool with zero annotation coverage, this is a significant gap in 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 a single, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded and appropriately sized, making it easy to understand quickly with zero waste.

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 complexity as a mutation operation (creating a list) with no annotations and no output schema, the description is incomplete. It lacks details on behavioral aspects, error handling, or what the tool returns, which are crucial for an AI agent to use it correctly in context.

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 100%, with clear descriptions for both parameters (title and type, including enum values). The description adds no additional meaning beyond the schema, such as examples or constraints. Baseline 3 is appropriate as the schema adequately documents parameters without extra value from the description.

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 verb ('Create') and resource ('new Cozi list'), specifying it can be either a shopping or todo list. However, it doesn't explicitly differentiate from siblings like cozi_add_item (which adds items to existing lists) or cozi_get_list (which retrieves lists), leaving some ambiguity about when to use this versus other list-related tools.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing authentication), when not to use it (e.g., for updating existing lists), or direct alternatives among siblings like cozi_edit_item for modifying lists. Usage is implied but not explicitly stated.

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