add_drum_pattern

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

No annotations are provided, so the description carries the full behavioral burden. It reveals one useful trait, that the result's 'lanes' explains where each lane landed, but omits whether existing notes are overwritten (the 'replace' flag is only defaulted in schema, not explained), whether the item_id must exist first, or how unmatched lane names are resolved beyond the schema's brief hint.

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 sentences, front-loaded with the core action, and the second sentence adds non-redundant return-value context. No filler, though the second sentence is a touch cryptic ('and why') without much elaboration.

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 9-parameter, nested-object mutation tool with no annotations and no output schema, the description covers the action and hints at the output ('lanes'), which is helpful. But it leaves gaps around side effects (replace behavior, whether an existing MIDI item is required) that an agent would need before invoking it correctly.

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 89%, so the schema already documents nearly every parameter (step, start, swing, channel, patching/velocity syntax in 'pattern', humanize). The description adds no parameter detail beyond what the schema supplies, 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 (programs) and resource (drums, step-sequencer style) on the track's drum instrument. It is distinguishable from siblings like add_midi_notes or write_bassline, though it never names the closest alternatives such as add_genre_groove or map_drum_kit to sharpen the boundary.

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 the tool is for step-sequencer-style drum programming but gives no explicit when-to-use, prerequisites (e.g. the item must already exist and be on a drum instrument), or when a sibling like add_midi_notes or add_genre_groove would be the better choice.

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