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

With no annotations, the description carries the full burden and does well: it discloses the required authorization level ('Editor role required'), the side effect emitted ('Emits video.updated'), and PATCH-style merge semantics. It omits reversibility and whether a file swap is destructive to the prior asset.

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?

Three dense sentences with the core action front-loaded, followed by the ID source, merge semantics, permission requirement, and event. Every clause carries information; nothing is padded.

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?

No output schema and no annotations, so the description must cover behavior — it does so with auth, partial-update semantics, event emission, and the ID source. It leaves the response shape and the effect of swapping a file's underlying asset unstated, but an agent has enough to invoke 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?

Schema description coverage is 100%, so the baseline is 3. The description loosely maps 'swap its file (`url`)' and 'rename/relabel' to parameters, but adds no syntax, constraints, or format detail beyond the schema's own per-field documentation (URL types, char limits).

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 precise verb and resource ('Change one video in a video surface') and enumerates the concrete mutations (swap file, rename, relabel). An agent can distinguish this from add_video and remove_video without opening any 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?

Gives explicit sourcing guidance ('Get video_id from list_videos') and clarifies partial-update behavior ('Omitted fields stay as they are'), which tells the agent it need not supply every field. It stops short of naming when-not-to-use or pointing at an alternative tool.

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