Happy Server MCP

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

No annotations are provided, so the description carries full burden. It states the tool creates a new item, implying a write operation, but lacks details on permissions, side effects (e.g., if it triggers notifications), error handling, or response format. This is inadequate 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 that directly states the tool's purpose and key parameters without unnecessary words. It is appropriately sized and front-loaded with essential information.

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 is a mutation (create) with no annotations and no output schema, the description is insufficient. It doesn't explain what happens after creation (e.g., returns an ID, error cases), behavioral traits, or integration with sibling tools, leaving significant gaps for agent usage.

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 parameter documentation in the schema. The description adds minimal value by reiterating that 'text' is optional, but doesn't provide additional context like character limits, formatting, or examples beyond what the schema already specifies.

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 ('Create a new Zen (todo) item') and specifies the resource ('todo item') with its core attributes ('title and optional description'). It distinguishes from siblings like happy_zen_list_todos (list) and happy_zen_update_todo (update), but doesn't explicitly differentiate from other creation-related tools (none in siblings).

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 (e.g., happy_zen_update_todo for modifications, happy_zen_set_todo_done for completion). It mentions optional parameters but offers no context about prerequisites, typical scenarios, or exclusions.

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