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

Annotations only declare readOnlyHint=false and destructiveHint=false, leaving the mechanism and result unexplained. The description fills that gap well: it discloses ffmpeg rendering, that the result is returned synchronously ('right away'), and that it is also persisted to list_my_videos. It omits any note on duration limits, cost, or failure behavior.

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?

The core action and the ordering constraint are front-loaded in the first two sentences, with optional parameters and usage trigger following. It is a dense single block with no wasted sentences, though the inline parenthetical lists make it slightly harder to scan than it could be.

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 correctly takes on the burden of describing the return value ('the finished, downloadable video url'), and it covers the required ordered-id input and where ids come from. A note on processing time or how to reference the saved output would make it fully complete.

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 description coverage is 100%, so the baseline is 3. The description restates the ordering rule ('the first id plays first') and the optional knobs (orientation, fps, quality), but these are already fully documented in the schema, so it adds little beyond the structured fields.

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 ('Stitch several of your Switch videos together into ONE video, played back-to-back') and even names the data source (list_my_videos). It is unambiguous about what the tool produces, but it never distinguishes itself from the sibling stitch_in_editor, so it falls 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?

The closing sentence gives an explicit trigger set ('whenever the user wants to combine, join, merge, or concatenate multiple clips into one'), which is clear usage context. However, it offers no when-not guidance and never mentions stitch_in_editor as the alternative, so the agent must infer the boundary itself.

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