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

The readOnlyHint annotation already establishes the safety profile. The description adds useful behavioral context by specifying what is returned (sequence, BPM, keys, lyrics, chord chart) and noting that chord charts can optionally be transposed, though it does not discuss pagination behavior beyond what the schema already provides.

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 a single efficient sentence that front-loads the core purpose and returned data, followed by a brief endpoint reference. No unnecessary text is included.

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?

With no output schema, the description helpfully lists the main returned fields so the agent understands the return content. All parameters are documented in the schema, and the read-only nature is covered by annotations, making this complete enough for correct invocation.

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 100%, so the schema already documents all five parameters. The description adds only marginal meaning, such as noting optional chord chart transposition and the source of song_id, both of which are already present in the schema descriptions. Baseline 3 is appropriate.

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 states a specific verb and resource: listing arrangements of a single song. It also enumerates the key returned fields (sequence, BPM, keys, lyrics, chord chart), distinguishing this clearly from sibling list tools such as elvanto_list_songs.

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 used when arrangements for one song are needed, and it points to elvanto_list_songs as the source of the required song_id. It does not explicitly state when not to use this tool or name competing alternatives, but the context is clear for this nested-resource list operation.

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