Things App MCP

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

Annotations declare readOnlyHint=true, indicating a safe read operation. The description adds valuable context beyond annotations: it specifies the implementation uses AppleScript and is macOS-only, which are critical behavioral traits not covered by annotations. It does not mention rate limits or error handling, but with annotations covering safety, this is sufficient for a high score.

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 two sentences with zero waste: the first states the core purpose, and the second adds essential platform and implementation details. It is front-loaded and appropriately sized, with every sentence earning 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?

Given the tool's low complexity (single parameter, read-only), no output schema, and rich annotations, the description is mostly complete. It covers purpose, platform constraints, and implementation method. However, it lacks details on return values (e.g., what data is included) or error cases, which would be helpful despite the absence of an output schema.

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 input schema has 100% description coverage, with the 'id' parameter fully documented. The description does not add any meaning beyond the schema (e.g., format examples or constraints), so it meets the baseline of 3 where the schema does the heavy lifting.

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 ('Get') and resource ('a specific to-do by its ID'), making the purpose explicit. It distinguishes from siblings like 'get-todos' (list) and 'get-recent-todos' (filtered list) by specifying retrieval of a single item via ID.

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 clear context: it's for retrieving a specific to-do when you have its ID, implying it should not be used for listing or searching. However, it does not explicitly state when to use alternatives like 'get-todos' for listing or 'search-todos' for searching, nor does it mention prerequisites (e.g., ID must exist).

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