marker_add_named

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

Description discloses the duplicate-name error condition ('Errors if a marker with this name already exists on the track') and confirms it creates rather than updates or deletes. It doesn't cover auth requirements, rate limits, or the behavior when the track_target does not exist. Non-destructive action is evident (adding a marker).

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?

Three clearly separated sections, compact 50-word description, and a clean args block. No wasted sentences.

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?

Sibling context provides a rich marker namespace. No output schema (but acceptable for an add action); no authentication, rate-limit, or track-existence precondition. Track_target description compensates partly.

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 is sparse (0% coverage). Description adds a little: 'track_target: Marker track {guid} from event_add_marker_track' provides some provenance, and 'position: Timeline position (seconds) >= 0' restates the schema. No constraints on the GUID, no default, and the fields are only lightly described.

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?

Description uses a specific verb 'add' and resource 'named marker', with 'destination' semantics that distinguish it from sibling marker_add_transition, marker_add_region, and marker_add_sustain_point. The error-if-duplicate behavior is explicitly stated, and the alternative marker_list is named. This is a clear and distinct 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?

Explicitly states using marker_list first to check for duplicates, providing a sequential alternative. However, it does not explicitly state when not to use the tool (e.g., for adding transition markers or sustain points), nor does it specify the prerequisite that the marker track must exist.

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