Things MCP

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

Without annotations, the description carries the burden of behavioral disclosure. It specifies the 'active' filter (distinguishing from archived/trashed projects), implying a read-only operation. However, it omits details about the return format, pagination behavior with max_results, or what constitutes 'active' in the Things app context.

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?

Extremely concise at four words. No filler content, though the brevity approaches under-specification. Appropriately front-loaded for a simple list retrieval operation.

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 single-parameter list tool, the description identifies what is retrieved ('active projects'). However, with no output schema provided, it should ideally specify that it returns an array/collection of project objects rather than leaving this implicit.

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 coverage is 100% for the single 'max_results' parameter, which has a complete description in the schema. The description adds no parameter-specific context, meeting the baseline expectation when the schema is self-documenting.

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?

Uses specific verb 'Get' with resource 'projects' and scope 'active'. The plural 'projects' distinguishes it from sibling 'things_get_project' (singular), and 'active' distinguishes from siblings like 'things_get_trash' or 'things_get_logbook'. However, it lacks explicit clarification about returning a collection vs. the singular variant.

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?

Provides no guidance on when to use this versus the singular 'things_get_project' or other project-related tools. No mention of prerequisites or when-not-to-use scenarios.

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