Things MCP

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds useful context about platform dependency ('macOS only') and implementation method ('Uses AppleScript'), which aren't covered by annotations. However, it doesn't describe error handling, return format, or performance characteristics.

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 (two short sentences) with zero wasted words. The first sentence states the core purpose, and the second adds essential implementation context. Every element earns its place.

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?

For a simple read operation with good annotations (readOnlyHint) and full schema coverage, the description provides adequate context about platform constraints and implementation. The main gap is the lack of output schema, but the description doesn't need to explain return values since it's a straightforward get-by-id operation.

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 the single parameter 'id' fully documented as 'The ID of the to-do to retrieve'. The description doesn't add any additional parameter semantics beyond what the schema provides, so the baseline score of 3 is appropriate.

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 specific action ('Get a specific to-do') and resource ('by its ID'), distinguishing it from sibling tools like 'get-todos' (list) and 'get-recent-todos' (filtered list). The phrase 'Uses AppleScript (macOS only)' further clarifies implementation constraints.

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 implies usage context by specifying 'by its ID' and 'macOS only', which helps differentiate from tools like 'search-todos' or 'get-recent-todos'. However, it doesn't explicitly state when to use this versus alternatives like 'get-todo-by-id' versus 'get-todos' for bulk retrieval.

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