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

Annotations already declare readOnlyHint, idempotentHint, and a closed-world scope, so the safety profile is covered. The description adds two genuinely useful behavioral facts beyond that: only *released* lyrics are returned, and at least one song yields no lyrics because it is an instrumental. It still says nothing about the return shape or failure behavior.

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 short, front-loaded sentences with zero padding. It is efficient, though the second sentence is arguably a fragment that could be merged more clearly with the first.

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 single-parameter, read-only, closed-world lookup with full schema coverage and no output schema, the description is adequate but thin: it does not tell the agent what a successful return looks like or what happens for the instrumental track. The album-level scoping and the instrumental caveat partially compensate.

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%: the slug param carries a 17-value enum and a pointer to list_songs, so the schema fully carries parameter meaning. The description adds nothing about the slug format or how to obtain it, which is the correct baseline when the schema does the heavy lifting.

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 identifies the resource ("the released lyrics of one song from All of It Was Ours") but phrases it as a noun fragment rather than an action, and it never distinguishes this from siblings like get_song or find_song, which a reader might expect to also surface lyrics. The specific album reference narrows scope somewhat, but the purpose is only implied.

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 guidance and no named alternative for retrieving song data versus lyrics. The one edge-case hint ("In Between Us is an instrumental") is a useful caveat but is not usage routing; nothing says when to reach for get_lyrics over get_song.

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