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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety behavior is covered. The description adds behavior beyond annotations: returning a {tracks} object and, on zero matches, exposing the actual mood and genre tags the library carries. This gives the agent useful failure-recovery information.

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, all information-dense and purposeful, with the core browse action and result shape front-loaded. The zero-match retry guidance earns its place rather than padding the description.

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 read-only browse tool with four optional filters, the description covers return shape, filter categories, downstream use, and an edge case (zero matches). It does not mention pagination or result ordering, but those are minor gaps given the simplicity and annotation coverage.

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 explains all four optional parameters. The description mostly restates the category values and adds downstream usage context, but it does not significantly deepen the meaning of individual parameters beyond what the schema provides.

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 states a specific verb and resource: 'Browse the audio library for background music and sound effects,' with the category dimension made explicit. It distinguishes the tool somewhat by describing its result feeding add_music_track / add_segment_sfx, but it does not explicitly differentiate it from sibling list_music_tracks.

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 provides clear usage context: it returns track ids that feed add_music_track / add_segment_sfx, which tells the agent how to use the results downstream. It also gives a retry strategy when zero matches occur, which is practical guidance. It does not explicitly name when not to use it or mention alternatives, so it lacks full exclusion guidance.

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