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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds genuinely useful context beyond that: the operation is FREE with no subscription, processing is asynchronous and returns a tool_job hashid with status queued, and free usage is rate-limited with per-file size/duration caps. It does not, however, state whether the original file is preserved or overwritten by an edit, which is the one behavioral question left open for a mutation tool.

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-loads the purpose and the operation list, then the usage workflow, then a per-operation param block. Every section is useful, though the per-operation param list partially duplicates the schema descriptions, adding length without new information in a few spots.

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 carries the return-value burden and does so: it explains the tool_job hashid, the queued status, the polling target, and where the downloadable URL eventually appears. Rate limits and error behavior are also flagged, so nothing an agent needs to call and complete this workflow 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%, so baseline is 3, but the description earns credit by mapping parameters to operations (e.g., trim requires start_ms and end_ms; rotate takes degrees and/or flip; compress takes target_mb OR crf) in a way the flat schema does not express. It stops short of documenting the crf range or aspect enum in the prose, leaving some detail to the schema.

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 (edit) and resource (already-uploaded video file), then enumerates the six supported operations (crop, trim, rotate, resize, compress, mute). An agent can distinguish this from edit_image and convert_media purely from the text.

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 an explicit workflow for local files (create_upload -> PUT bytes -> pass id here) and explicitly instructs NOT to call complete_upload, naming the consequence (starts the paid clip pipeline). It also names the follow-up tool (get_tool_job_status) and the condition for polling.

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