Things MCP

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

Annotations provide readOnlyHint=true and openWorldHint=true, indicating safe, read-only operations with flexible inputs. The description adds context by specifying the navigation aspect (implying UI interaction) and listing built-in list IDs, but does not disclose further behavioral traits like rate limits, authentication needs, or what 'show' entails beyond navigation. With annotations covering safety, a 3 is appropriate as the description adds some value but not rich behavioral details.

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 appropriately sized with two sentences: the first states the purpose and scope, and the second lists built-in list IDs for clarity. Every sentence earns its place by providing essential information without redundancy, making it front-loaded and efficient.

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 moderate complexity (navigation with three parameters), rich annotations (readOnlyHint, openWorldHint), and 100% schema coverage, the description is mostly complete. It covers what the tool does and provides examples, but lacks details on output (no output schema) or explicit usage boundaries. For a read-only navigation tool, this is sufficient but not exhaustive.

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 clear descriptions for 'id', 'query', and 'filter' parameters. The description adds minimal value by listing built-in list IDs (which are already in the schema for 'id'), but does not explain parameter interactions (e.g., 'id' overrides 'query') or provide additional semantics beyond the schema. Baseline 3 is correct when 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 specific action ('Navigate to and show') and the resources involved ('a list, project, area, tag, or to-do in Things'), distinguishing it from siblings like 'get-areas' or 'search' which retrieve data rather than navigate. It also lists built-in list IDs, providing concrete examples of what can be shown.

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 by specifying what items can be shown (lists, projects, areas, tags, to-dos) and listing built-in list IDs, giving clear context for when to use it. However, it does not explicitly state when not to use it or name alternatives (e.g., 'get-todos' for retrieving data without navigation), which prevents a perfect score.

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