Things MCP

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

Annotations declare readOnlyHint=true, which the description aligns with by using 'Get' (implying read-only). The description adds context about platform dependency ('macOS only') and implementation detail ('Uses AppleScript'), which are useful beyond annotations. However, it doesn't disclose behavioral traits like rate limits, error handling, or return format, keeping it at a baseline level.

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 short sentences with zero waste: the first states the purpose, and the second adds essential technical constraints. It's front-loaded with the core functionality and appropriately sized for a simple tool.

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 simplicity (0 parameters, read-only, no output schema), the description covers the basic purpose and platform constraints adequately. However, it lacks details on output format (e.g., what 'projects' includes) and doesn't leverage sibling context for differentiation, making it minimally viable but with gaps.

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 tool has 0 parameters, and schema description coverage is 100% (though empty). With no parameters to document, the description doesn't need to compensate, and the baseline for 0 parameters is 4. The description appropriately doesn't discuss parameters, which is correct for this case.

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 'projects from Things', making the purpose specific and understandable. However, it doesn't distinguish this tool from sibling tools like 'get-project-by-id' or 'get-areas', which would require explicit differentiation to earn a 5.

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 like 'get-project-by-id' or 'search'. It mentions 'Uses AppleScript (macOS only)', which is a technical constraint but not usage guidance. Without explicit when/when-not instructions or named alternatives, this scores low.

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