add_fx

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

No annotations exist, so the description carries the full burden, and it does not disclose key mutation traits: where in the FX chain the plugin is inserted, what happens if the plugin name does not match, whether the track must already exist, or whether the operation is idempotent. Only the plugin-name format and a list of built-ins are provided.

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?

Front-loaded with the action, then the naming constraint, then the built-in list. Every sentence is relevant, though the enumerated built-in plugin names take a fair amount of space for a hint that arguably could be shorter.

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 is simple (2 required params, no nested objects, no output schema), and the description covers what fx_name should look like. However, with zero annotation coverage it leaves the mutation behavior and track_index semantics unaddressed, which is a meaningful gap for a state-changing tool.

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 0%, so the description must compensate. It adds real meaning for fx_name (exact FX-browser name, plus a concrete list of built-in Cockos names), but gives no clarification for track_index — its indexing base, validity, or whether it must reference an existing track.

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?

Specific verb+resource ("Add an FX plugin to a track") with the scope explicitly narrowed to a track, which cleanly separates it from sibling add_master_fx, list_track_fx, and remove_fx. The second sentence clarifies the plugin domain (VSTi vs VST/AU), so an agent knows it is the generic FX-insertion tool.

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 implied by the verb — call it when a track needs a new plugin — but there is no explicit when/when-not guidance and no routing to alternatives such as load_fx_preset, insert_track_template, or add_master_fx. The naming convention note ("exact plugin name as shown in REAPER's FX browser") is helpful context but is parameter guidance rather than use-case guidance.

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