motion_open

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the indexing action, the prerequisite, and the return summary, which is useful. However, it does not mention potential side effects such as whether the file is locked, whether the operation is read-only, or behavior if the file is already open.

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 concise sentences, each adding value: the first states the action and resource, the second explains the prerequisite and the return summary. It is front-loaded and contains no extraneous information.

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?

The description covers the purpose, the prerequisite, and the return summary. Given the simple one-parameter open/index operation and the presence of an output schema, this is fairly complete. It could add a note about state lifecycle (e.g., that the file stays open until closed with motion_save_as), but it's not a critical gap.

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 schema has a single path parameter with 0% description coverage, and the tool description doesn't explicitly explain the parameter. However, mentioning specific file types (.motn/.moti) implies the path should point to such a file. For a single obvious parameter, this is adequate, though the description could have directly stated 'path'.

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 uses a specific verb phrase 'Open and index' with the resource '.motn or .moti file', clearly stating the tool's primary action. It also establishes the tool's unique role as the mandatory first step with 'Required before any other tool can operate on it', effectively distinguishing it from siblings like motion_open_in_motion.

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 a use condition: 'Required before any other tool can operate on it', which tells the agent when this tool must be called. It doesn't name alternative tools or exclusion scenarios, but the prerequisite provides clear contextual guidance.

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