add_midi_notes

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

With no annotations provided, the description carries the full behavioral burden. It does disclose one genuinely useful, non-obvious trait — 'The item grows to fit notes past its end' — which the schema does not state. But it omits other behavior a mutation tool needs to surface: what happens to existing notes by default (overwrite vs append), what the call returns, and any auth/precondition requirements.

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, front-loaded with the primary action and followed by one high-value behavioral fact (auto-growth). No filler, no restating the tool name, and every clause 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 3-param mutation tool with no annotations and no output schema, the description is adequate but thin: it never clarifies the append-vs-replace default, the precondition that a MIDI item must exist, or what the call yields. The auto-grow note helps, but not enough to call the definition fully complete.

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 67%: item_id, replace, and every nested Note field (pitch, start, length, channel, velocity) are documented in the schema, including units and defaults. The description adds no parameter meaning beyond that, so the baseline 3 for schema-doing-the-work 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?

The description gives a specific verb+resource ('Writes notes into a MIDI item') and even illustrates content types, so the core action is unambiguous. However, it does not distinguish itself from closely related siblings like edit_midi_notes, write_melody, write_bassline, or add_chord_progression, leaving the agent to infer that this is the low-level primitive.

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?

There is no explicit when-to-use or when-not-to-use guidance. Nothing tells the agent whether to prefer add_midi_notes over edit_midi_notes, write_melody, or write_bassline, nor that a MIDI item must already exist (a dependency on create_midi_item). Usage is only implied by the verb 'Writes'.

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