delete_library_caches

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

Annotations already carry the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=true) and the description is consistent with them, so no contradiction. The description adds the specific scope (library caches) and the endpoint, but does not disclose side effects such as whether caches regenerate on demand, whether active streams are disrupted, or whether disk space is reclaimed.

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?

One tight sentence followed by the HTTP endpoint. The action is front-loaded, there is no filler, and every element 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 parameterless call with annotations and an output schema present, the description is nearly sufficient. The gap is that 'library caches' is undefined (thumbnail caches? search indexes? metadata caches?) and no consequence or regeneration behavior is stated, which matters because this is a destructive operation affecting the whole library.

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?

The tool takes zero parameters, so there is nothing the description needs to add beyond what the schema implies; the 0-parameter baseline of 4 applies. The endpoint 'DELETE /library/caches' effectively communicates that the call is fully specified with no arguments.

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 ('Delete library caches') and reinforces it with the exact endpoint 'DELETE /library/caches'. This distinguishes it from the many section- and metadata-scoped delete_library_* siblings, though it never defines what 'caches' encompasses, so it stops just short of a 5.

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?

There is no guidance on when to invoke this tool versus alternatives: no trigger conditions (e.g., freeing disk space, clearing stale artwork), no prerequisites, and no mention of when a section-scoped cache operation would be more appropriate. Among dozens of delete_library_* siblings, nothing helps an agent choose this one.

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