Browse and filter 300+ instrument voices by name or category to choose the right voice when adding an instrument.
Lists the app's voices (over 300), to pick from when adding an instrument. Filter them, since the full list is long.
| Name | Required | Description | Default |
|---|---|---|---|
| query | No | Text to look for in the name or category, like "bass" or "piano". | |
| category | No | Exact category, like MIDI, CHIPTUNE, LEAD or DRUMKIT. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the result set is large (300+ entries) and the full list is long, which warns the agent to narrow the query. It omits what a voice record contains or any pagination behavior, keeping it below a 5.
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 tight sentences with no filler. The resource and its scale are front-loaded, and the filtering advice follows immediately.
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 read-only list tool with two optional params and no output schema, the description covers what it returns at a high level (voices) and how to keep results manageable. A brief note on what fields a voice entry exposes would close the remaining gap left by the absent output schema.
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%, so both parameters (query, category) are already documented with examples in the schema. The description only says 'filter them' generically and adds no syntax, matching rules, or interaction between query and category, so the baseline 3 applies.
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?
States a specific verb and resource ('Lists the app's voices') and adds scale and purpose ('over 300', 'to pick from when adding an instrument'), which implicitly distinguishes it from mutation siblings like add_instrument. It stops short of naming an explicit alternative or contrasting tool, so it lands at 4 rather than 5.
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?
'Filter them, since the full list is long' gives implied usage guidance (use the filters when the full list would be unwieldy) but never states when not to call it or which sibling to use instead. There are no prerequisites or exclusions, so the agent must infer the workflow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.