library_coverage_report

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

There are no annotations, so the description carries the behavioral disclosure burden. It explicitly states 'Read-only,' assuring no mutation, and it describes what the report contains. It could add caveats about scan caps or pagination, but the read-only guarantee is meaningful and clearly 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?

Two sentences with no filler: the core purpose is front-loaded, the output categories are named, and the read-only safety trait is stated. 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 6-parameter report tool with no output schema, the description gives enough orientation: it names what is reported and confirms no side effects. Since the input schema fully documents all parameters, the remaining gap is mostly the lack of routing guidance against similarly named siblings.

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 description does not need to reinvent parameter docs. The description references the two output categories but does not add meaning beyond what the parameter schema already provides. This is an appropriate baseline for fully self-documenting parameters.

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 names a specific verb and resource: 'Report coverage between your saved tracks and playlists,' and enumerates the two computed categories (orphan saved tracks and unsaved playlist items). It is clear and specific, but it does not explicitly distinguish itself from close siblings like saved_vs_playlist_coverage or unsave_orphan_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 implies a clear usage context: analyze gaps between saved tracks and playlists. However, it provides no explicit when-to-use guidance, no alternatives, and no exclusion criteria relative to overlapping report or mutation tools.

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