reference_song_lookup

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

No annotations are provided, so the description must carry the burden of transparency. It states the tool 'looks up' and 'returns' data, making it clear that it is a non-destructive read operation. It also discloses the nature of the output (BPM, key, form, energy curve, signatures), but does not mention edge cases like missing names or invalid genres.

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 two sentences: the first states the purpose, the second explains the parameters and output. It is concise, front-loaded, and contains no redundant information.

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 there is no output schema, the description lists the returned fields (BPM, key, form, energy curve, signatures) and notes they can be used as composer inputs. It does not define 'energy curve' or 'signatures' in detail, but they are domain-specific enough for the intended audience. Error behavior is not mentioned, but the core usage is fully covered.

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?

Both parameters (`name` and `genre`) are explained in the description, including the constraint that `name` must be a key in REFERENCE_SONGS and the relationship between them (OR). This fully compensates for the absence of parameter descriptions in the schema.

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's purpose with a specific verb ('look up'), a defined resource ('musical hints for a song'), and the exact parameters (`name` or `genre`). It distinguishes itself from sibling tools like `reference_song_list` by focusing on musical hints rather than just listing references.

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 clear usage instructions: pass `name` (one of the keys in REFERENCE_SONGS) or `genre` to list all references in that genre. It does not explicitly name alternatives or state when to prefer this over sibling tools, but the condition for use is implicit in the parameter guidance.

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