playlist_changelog

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

With no annotations provided, the description carries the behavioral disclosure burden. It states exactly that the operation is read-only and makes no API calls, which is valuable and not inferable from the schema alone. It could add more detail about file lookup or failure behavior, but the key safety traits are disclosed.

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 tight sentences with no filler. It front-loads the core operation, then adds a memorable usage hook and a critical behavioral note ('Read-only, no API calls'). Every sentence earns its place.

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 tool with a fully documented schema and no output schema, the description covers the primary inputs and expected result categories (added, removed, kept, reordered). It does not explain edge cases like missing snapshots or mismatched playlists, but overall an agent has enough to invoke 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 100%, so the schema already documents every parameter. The description adds conceptual framing ('older → newer', 'exact first, then substring') but does not materially expand on parameter semantics beyond the schema, matching the baseline.

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 identifies the verb ('Diff'), resource ('ONE playlist across two backup snapshots'), and the output categories (added, removed, kept, reordered). It is specific and useful, though it does not explicitly name or differentiate itself from similar sibling tools like snapshot_changelog or diff_playlist_snapshots.

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 'what changed since last week' framing gives clear situational context for when to use this tool. It does not list exclusions or explicitly point to alternatives, so it falls short of the top score.

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