filter_by_genre

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

With no annotations, the description carries the behavioral burden. It explicitly discloses read-only behavior, case-insensitive matching, and that genre tags come from the sidecar. This goes beyond a bare operation statement, though it leaves sidecar prerequisites and failure behavior implied rather than explicit.

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?

Three sentences with no filler. The core action is front-loaded, the output contract is stated, and the read-only safety note is included. 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 4-parameter read-only tool with no output schema, this description is largely complete: it explains what is filtered, where tags come from, case sensitivity, and how the output can be consumed. The only notable gap is that 'sidecar' is referenced without explaining what it is or what happens if it lacks genre data.

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 parameters are already well documented. The description adds contextual value by clarifying the output is playlist-ready URIs, but it does not add parameter-level detail beyond what the schema already provides. 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 clearly states the verb 'List', the resource ('URIs of your saved tracks or albums'), and the filtering condition (artists carrying a given genre tag). It distinguishes itself from nearby sibling tools like library_genre_report or genre_dive_search by focusing on saved-library filtering and URI output.

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 gives clear context by specifying the input source (saved tracks/albums) and the intended downstream use ('directly usable as create_playlist / add_to_playlist input'). It does not explicitly name alternative tools or state when not to use them, so it stops short of a 5.

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