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

Even with no annotations, the description fully discloses behavior: it copies notes from B to A while preserving absolute positions, extends region A's duration, deletes region B, and handles gaps with silence. No contradictions.

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?

The description is well-organized with a concise main statement followed by behavior details, use cases, parameter explanations, return info, and an example. Every sentence adds value.

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?

The description covers all key aspects: behavior, parameters, use cases, and return value. It could mention error conditions (e.g., regions on different tracks) but is otherwise thorough.

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 coverage is 0%, but the description adds detailed explanations for each parameter (unit_index, track_index, region_index_a, region_index_b) in plain language, making their roles clear.

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 it merges two note regions on the same track. However, it does not explicitly differentiate from sibling tools like 'consolidate_region' or 'flatten_note_regions', which might have overlapping functionality.

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 provides relevant use cases (joining verse+chorus, consolidating split regions, etc.) and notes that regions need not be adjacent. However, it lacks explicit guidance on when not to use this tool versus alternatives.

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