reaper_call

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

No annotations are provided, so the description carries the full burden. While the description does explain pointer return format ({"__handle":"hN"}) and hints that handles can be passed back in, it omits key behavioral details: what happens if the function doesn't exist, whether calls are synchronous, whether they mutate project state, or error behavior. Since this can execute arbitrary ReaScript functions, the lack of safety/behavioral disclosure is a significant gap.

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?

Highly concise: two sentences plus an example. The core purpose and pointer format are front-loaded, and the example is illustrative without extraneous content. Every sentence earns its place.

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 generic function-calling tool, the description gives the essential call pattern and pointer handling, but it lacks crucial operational context: no error handling, no mention of argument serialization rules, no discussion of side effects, and no differentiation from sibling tools like run_lua. With no annotations and no output schema, the description should do more to cover these gaps.

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 for the bare schema. It does explain func as a ReaScript function name and args as the argument list, with an example (CountTracks with arg 0). However, it doesn't clarify what argument types are supported, how args map to ReaScript parameters, or what the pointer handle string structure means beyond an example. It adds some meaning but leaves ambiguity for arbitrary functions.

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 action (call any ReaScript function by name) and resource (ReaScript functions in REAPER). It also shows an example invocation with func and args. However, it doesn't explicitly differentiate from sibling tools like run_lua, which also executes scripts, leaving some ambiguity about when to use reaper_call over run_lua.

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?

No guidance is given on when to use this tool vs alternatives such as run_lua or project tools. The sibling context includes run_lua, which could overlap significantly, and the description provides no criteria for choosing between them. It also doesn't mention constraints on function names, argument types, or error behavior.

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