fx_get_instrument

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

Without annotations, the description discloses return value (index + params or -1) but does not mention side effects, permissions, or other behaviors. It adequately describes the read operation but falls short of full transparency.

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?

Extremely concise: two lines and an args list. Every sentence is necessary and front-loaded.

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?

Given it's a simple lookup tool with one parameter and no output schema, the description fully explains the input and return value. No 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?

The schema has one parameter (track_index) with 0% coverage, but the description adds meaning by stating it is 0-based, which is not in the schema. This compensates for the coverage gap.

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 clearly states the tool finds a VSTi instrument on a track, returning its index and params or -1 if none. It distinguishes from sibling fx tools like fx_add or fx_get_chain.

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 implies usage for locating an instrument but provides no explicit guidance on when to use this tool vs alternatives like fx_get_chain or fx_list_installed. No exclusions or context cues.

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