fcpkit_libraries

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

Beyond the readOnlyHint annotation, the description discloses key operational behavior: it uses AppleScript, refuses when FCP is not running or two copies are running, and never launches FCP. These are exactly the preconditions an agent needs to avoid failed or surprising calls.

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 tightly written sentences front-load the purpose and follow with the critical failure behaviors. Every clause earns its place, including the parenthetical '(AppleScript, read only)' and the 'never launches FCP' guarantee.

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?

The tool is simple and its core scope plus refusal behavior are well covered, but with no output schema and no parameter documentation, the definition leaves the two input parameters unexplained. An agent can call it with defaults, but cannot make informed choices about timeout or durations from the description.

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 schema has two parameters, 'timeout' and 'durations', with 0% description coverage, and the description says nothing about either. Since schema coverage is low, the description should compensate for this gap, but it provides no meaning, units, or effect for the 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 gives a specific verb ('List') and precise resources ('libraries, events and projects') scoped to the running Final Cut Pro application. It is immediately distinguishable from sibling tools such as timeline_diff or effects_check without needing to open the 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?

The context of use is implied by 'open in the running Final Cut Pro', but the description never states explicit when-to-use or when-not-to-use guidance relative to siblings like fcpkit_brief. The precondition 'Refuses if FCP is not running' is helpful but is behavioral rather than a usage routing rule.

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