Things App MCP

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

The description adds valuable behavioral context beyond annotations: 'Uses AppleScript (macOS only).' This discloses platform limitations not covered by the readOnlyHint annotation. The annotations already indicate it's a read-only operation, so the description appropriately focuses on additional constraints rather than repeating safety information.

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 perfectly concise and front-loaded: two sentences that efficiently cover purpose, constraints, and platform limitations. Every word earns its place with no redundancy or 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?

For a read-only retrieval tool with good annotations and full parameter documentation, the description is reasonably complete. It covers the core purpose, usage constraint, and platform limitation. The main gap is the lack of output schema, but the description doesn't need to explain return values since that's the schema's role when available.

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?

With 100% schema description coverage, the input schema already fully documents all four parameters. The description adds marginal value by emphasizing 'Specify exactly one source,' which clarifies the mutual exclusivity of parameters. However, it doesn't provide additional semantic context beyond what's in the schema descriptions.

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 tool's purpose: 'Get to-dos from Things by list, project, area, or tag.' It specifies the verb ('Get') and resource ('to-dos'), and mentions the source options. However, it doesn't explicitly differentiate from sibling tools like 'get-recent-todos' or 'search-todos', which reduces it from 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?

The description provides clear usage context: 'Specify exactly one source.' This gives explicit guidance on how to use the parameters. It also implies when to use this tool (for filtered retrieval) vs. alternatives like 'get-recent-todos' (for recent items) or 'search-todos' (for keyword searches), though it doesn't explicitly name these alternatives.

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