Things MCP

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

Annotations provide openWorldHint: true, indicating flexibility in parameter usage. The description adds value by listing the specific fields that can be updated (title, notes, dates, tags, etc.), which goes beyond the annotations. However, it does not disclose behavioral traits like rate limits, error handling, or what happens when only some fields are provided, leaving room for improvement.

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 front-loaded with the core purpose and requirements, followed by a concise list of updatable fields. It avoids redundancy and uses efficient phrasing, though the list of fields could be slightly more structured (e.g., grouped by category) for optimal readability.

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 complexity of 23 parameters and no output schema, the description adequately covers the tool's purpose and scope. It lists the updatable fields, which helps contextualize the many parameters. However, it lacks details on return values or error cases, which would be beneficial for a mutation tool with no output schema.

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 already documents all 23 parameters thoroughly. The description adds minimal value by summarizing the updatable fields but does not provide additional syntax, format details, or usage nuances beyond what the schema specifies. This meets the baseline for 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 verb 'update' and resource 'existing to-do in Things', distinguishing it from sibling tools like 'add-todo' (creation) and 'update-project' (different resource). It specifies the exact operation with the required parameters, making the purpose unambiguous.

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 explicitly states 'Requires the to-do ID and your Things auth-token', providing clear prerequisites. However, it does not specify when to use this tool versus alternatives like 'update-project' or 'add-todo', nor does it mention any exclusions or specific scenarios where this tool is preferred over others.

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