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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds useful behavioral context beyond that: it reports a coverage measure and lists gaps only when they are longer than a second, which tells the agent what to expect in the result without a contradiction.

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 tight sentences with no filler. The purpose is front-loaded and the usage guidance follows immediately.

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?

With no output schema, the description usefully states what the report includes: a coverage amount and suspicious gaps longer than one second. It stops short of describing the exact return shape or how coverage is expressed, but it is sufficient for an agent to call the tool correctly.

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?

There is only one parameter (jobId) and schema coverage is 100%, so the schema already explains it as 'The job to inspect.' The description does not add further detail about jobId, so the 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 gives a specific verb ('Report') and resource (coverage of the source timeline by subtitles), and adds what the report contains: coverage amount plus a list of gaps over one second. This clearly separates it from siblings like lunara_qa_contract or lunara_readability, which are not about timeline coverage.

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?

It explicitly recommends using the tool 'before shipping a long video,' giving a clear context for invocation. It does not name an alternative tool or an explicit when-not-to-use condition, keeping it 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.