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

With no annotations provided, the description carries the full behavioral burden and does well: it discloses that the call spends the user's credits, requires a public videoUrl, renders a live preview in capable hosts, and that polling must be skipped there. It does not cover failure behavior, credit cost magnitude, or processing time, so it stops just short of a 5.

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?

Front-loaded with purpose, then prerequisites, then host-conditional polling guidance — a sensible order. It is long for a description and repeats itself ('never assume defaults, never infer unstated preferences' restates the preceding sentence), but almost every clause carries routing or constraint value.

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 credit-spending, 9-parameter tool with no annotations and no output schema, the description covers the critical unknowns: consent gating, input URL constraints, preview rendering, and the polling alternative. The gaps are secondary parameter definitions (sourceLang/targetLang/limit) and any statement of what the call returns.

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 56%, so the description must compensate, and it partly does: it frames the user-facing choices (aspect ratio, captions/style, number of clips, clip length) and explains that clip length is irrelevant when query is set. However sourceLang, targetLang, and limit remain unexplained in both places, and the ratio/captionStyle enum semantics come from the schema rather than the description.

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?

Opens with a concrete verb+resource ('Turn a long video into short clips') and enumerates the request types it covers (clip, cut, chop, trim, repurpose, find moments). It also names the siblings it coordinates with (wait_for_clipping, clipping_status), so an agent can separate it from the status/polling tools without opening schemas.

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?

Explicit when-to-use (any clipping/repurposing/highlight request), explicit gating (do not call until the user chose aspect ratio, captions, clip count, clip length), and explicit host-conditional behavior for polling. This is close to a complete decision procedure, including what to do instead in preview-capable vs preview-less hosts.

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