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

Annotations already declare readOnlyHint/idempotentHint and openWorldHint=false, so the safety profile is covered. The description still adds genuinely useful context beyond them: free, no API key required, makes no network calls, and the 30-minute limit per job. It stops short of describing the shape of an individual section's output, but the output schema covers that.

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 paragraphs: the first says what it covers plus operational facts, the second says when to use it and how to parameterize. No sentence is filler and the key constraint (free, no key) is front-loaded.

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 zero-required-parameter reference tool with an output schema, the description supplies everything an agent needs: coverage scope, trigger conditions, parameter behavior, and the cost/auth profile. Nothing essential is missing.

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 coverage is 100% and the enum self-documents the section names, so the baseline is 3. The description adds real meaning on top by explaining what the values do ('topic selects one section; all returns everything'), which resolves the ambiguity of the 'all' default.

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?

States a specific verb ('Explains') and resource ('the option values accepted by create_clip_job and recut_clip_job'), then enumerates the domains covered (video modes, caption styles, pricing, etc.). An agent can distinguish this reference tool from the sibling job-creation tools without opening 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?

'Use it when the user asks what a style looks like, which mode fits their video, or how much processing costs' gives concrete trigger conditions, and naming create_clip_job/recut_clip_job as the consumers clarifies the relationship to alternatives. The 'topic selects one section; all returns everything' line completes the routing instruction.

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