search_library

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the meaningful scoping constraint (results are restricted to the user's saved library) and caps result volume via the documented 1–25 limit, but it says nothing about auth requirements, ordering/relevance of results, or behavior on empty matches.

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?

Front-loaded with the scope statement and the routing alternative, then the parameter block. Every line earns its place; the types enumeration and limit range are load-bearing, not padding.

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 three-parameter search with an output schema (so return shape needn't be explained), the definition covers scope, the alternative tool, and all parameter constraints. The only minor gap is result ordering/relevance behavior, which an agent might want when choosing between library and catalog search.

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 coverage is 0% – the schema only names the properties with a bare integer default for limit and no enum for types. The description fully compensates: it gives the valid comma-separated values for types (library-songs/albums/artists/playlists) and the 1–25 bound with default 10 for limit, none of which appear 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?

States a specific verb (search) plus a precisely bounded resource (only content saved in the user's Apple Music library) and immediately contrasts it with search_catalog. An agent can distinguish this from the sibling catalog search without opening either schema.

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?

Explicitly names the alternative and the condition that selects it: 'To search all of Apple Music, use search_catalog instead.' This is exactly the when-not-to-use guidance that differentiates the two search tools.

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