live_add_marker

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

With no annotations at all, the description carries the full behavioral burden. It does disclose one genuinely useful side effect — "The playhead is left where it was" — which an agent could not infer from the schema, but it is silent on what is returned (e.g. the new marker's identifier), what happens on an out-of-range or duplicate position, and whether the change is undoable.

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?

Two sentences, both front-loaded with the key facts (what it does, where it places the marker, the default, and the non-side-effect on the playhead). Nothing redundant or padded.

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?

For a simple zero-required-parameter mutation tool with no output schema, the definition covers placement semantics adequately, so nothing blocks a correct call. It stops short of saying what the call yields on success or how failures surface, which matters given the live-DAW context and absence of annotations.

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 coverage is only 33% (the `name` property has no description), so the prose must compensate. It usefully adds the default ("default: the playhead") and the seconds-or-bars convention for `at`, and implies `name` is optional, but it never explains the separate `seconds` parameter or when to use it instead of `at`, leaving an unresolved overlap the agent must guess at.

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 gives a specific verb+resource ("Add a marker in the running Studio One") plus scope details (position in seconds or bars, default playhead, optional name), which clearly separates it from siblings like live_rename_marker, live_delete_marker and live_markers. It never names an alternative explicitly, but the operation is 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?

Usage is only implied: the tool obviously applies to adding, and the default-to-playhead note tells the agent calling it requires no arguments at all. There is no explicit guidance on when to prefer this over a sibling (e.g. versus live_markers for inspection) or any preconditions such as needing markers enabled or a focused song.

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