fl_set_playlist_track_state

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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the write/non-idempotent nature is carried by structured data. The description adds one behavioral nuance: 'toggle-only selection is dispatched at most once,' which is helpful but not elaborated (e.g., does this mean repeated selection toggles are coalesced?). It doesn't mention the concurrency guard or what happens to unspecified states, but annotations and schema partially cover the safety profile.

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, purpose first, with zero filler. The behavioral nuance is attached in a clear second clause. It is front-loaded and economical.

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 tool has six parameters with optional fields and a concurrency guard, but the description does not explain what null means for mute/solo/selected (presumably 'leave unchanged'), nor does it clarify the interaction between expected_before and session_fingerprint. Given the high schema coverage and annotations, an agent can probably call it correctly, but the absence of null semantics and a more explicit statement about the effect of a write is a measurable completeness 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?

Schema description coverage is 100% and each parameter has a descriptive line (e.g., 'Absolute mute state,' 'Optional bridge/project-session fingerprint'). The description adds value on the 'selected' behavior with the at most once note, but does not illuminate expected_before or session_fingerprint beyond schema text. Since the schema carries the parameter burden, the description plates at the baseline 3.

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 states a specific verb and resource ('Set Playlist states') and the schema confirms it covers mute, solo, and selected states on a playlist track. Though 'Playlist states' is a bit terse, the tool name and sibling context (e.g., fl_set_playlist_track_identity) distinguish it from identity-setting tools. It doesn't enumerate the exact states in the description, but the resource and verb are sufficiently clear.

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 offers no explicit guidance on when to prefer this tool over alternatives. It doesn't mention that it operates on Playlist tracks (vs mixer tracks), when to use the expected_before/session_fingerprint concurrency guards, or how it differs from identity manipulation. The single sentence is behavioral, not navigational. For a mutation tool with many siblings, this is a clear gap.

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