marker_set_region

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 indicates mutation ('Move/resize') and enforces parameter constraints (position >= 0, length > 0), but it does not reveal potential side effects, failure modes, or whether the operation is reversible. It omits details about what happens if the target is invalid or if the marker is not a region-type, leaving the agent with incomplete expectations.

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 exceptionally efficient: a one-sentence purpose followed by a clean arg list with inline constraints. Every word contributes to understanding, with no filler or redundancy. It is front-loaded with the main action and then details the parameters in a structured way.

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 simplicity (3 parameters, no output schema, no annotations), the description covers essentials: what it does and parameter meanings. However, it omits information about return values, error handling, potential exceptions, and any prerequisites (e.g., the marker must already exist as a region). Since there are many sibling tools, more context on when this tool is appropriate versus others would improve completeness, but the current description is minimally sufficient.

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 input schema has 0% description coverage, so all parameter meaning must come from the description. The description adds value by specifying each parameter: target is a Region GUID, position is a new start in seconds with a lower bound, length is a new length in seconds with a positive bound. This clarifies types, units, and constraints beyond the bare schema, fully compensating for the schema's lack of descriptions.

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: 'Move/resize a region-type marker' and specifies the types (loop region, transition region). This distinguishes it from other marker tools like marker_set_position (which likely handles point markers) and marker_add_region (which creates a region). The verb and resource are explicit, leaving no ambiguity about its purpose.

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 'region-type marker' and the types (loop/transition region), but it does not explicitly mention when not to use it or compare it to alternatives like marker_set_position. There is no statement about prerequisites (e.g., marker must exist) or exclusions. The information is sufficient but lacks explicit guidance on tool selection.

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