Things App MCP

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

Annotations provide openWorldHint=true, indicating flexibility, but the description adds context about supported fields and the ability to create initial to-dos. However, it doesn't disclose behavioral traits like whether the tool requires authentication, rate limits, or what happens on conflicts (e.g., duplicate titles). No contradiction with annotations.

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 a single, efficient sentence that front-loads the core purpose and enumerates supported features. It avoids redundancy but could be slightly more structured, such as separating core vs. optional parameters.

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 13 parameters, no output schema, and minimal annotations, the description adequately covers the tool's purpose and key inputs. However, it lacks details on return values, error conditions, or advanced usage (e.g., handling of dates like 'someday'), leaving gaps for an agent to infer behavior.

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%, so the schema fully documents all 13 parameters. The description lists key parameters (title, notes, when/deadline dates, tags, area assignment, initial to-dos) but doesn't add meaning beyond what's in the schema, such as explaining interactions (e.g., areaId vs. area precedence) or constraints. Baseline 3 is appropriate given high schema coverage.

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 action ('Create a new project') and the resource ('in Things'), with specific details about supported fields (title, notes, dates, tags, area assignment, to-dos). It distinguishes from siblings like 'add-todo' (creates tasks) and 'update-project' (modifies existing projects).

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 for creating new projects but doesn't explicitly state when to use this vs. alternatives like 'update-project' for modifications or 'add-todo' for standalone tasks. No guidance on prerequisites, such as whether areas must exist first, or exclusions.

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