pin_playlist

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

With no annotations present, the description bears the full burden of disclosing behavioral traits. It states the core mutation but does not mention authentication requirements, whether following is idempotent, the public/private default, or what happens if the playlist is already followed. The endpoint line adds little behavioral insight beyond what the action already implies.

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 very short and front-loaded, with no redundant prose. The endpoint snippet is mildly useful but not strictly necessary; overall the structure is efficient, though it sacrifices behavioral context for brevity.

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 simple mutation tool with no annotations and no output schema, the description is too sparse. It lacks guidance on when to use the tool, how it relates to siblings, and behavioral consequences. The schema covers parameters, but the surrounding decision context is missing.

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 parameters including 'public' and 'playlist_id'. The description adds no additional parameter-level meaning beyond repeating the playlist ID in the endpoint path, so the baseline score of 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 clearly states the action ('Follow (pin)') and the resource ('a playlist to your library'), making the tool's purpose apparent. It does not explicitly differentiate itself from siblings like playlist_to_library or unpin_playlist, but the meaning is reasonably specific.

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?

No guidance is provided about when to use this tool versus alternatives such as unpin_playlist or playlist_to_library. The HTTP endpoint is an implementation detail, not usage direction. An agent must infer appropriate use from the tool name alone.

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