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

Annotations only declare it is non-read-only, non-destructive and open-world. The description adds genuinely new behavioral facts: it launches a background job, consumes credits, and hands back a project id consumed by wait_for_video_project. That is real transparency beyond structured fields, though cost amount and failure behavior are unstated.

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 short sentences, front-loaded with what the tool does, followed by the workflow and cost implication. Nothing is redundant with the title or name.

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 an async job-creating tool with an output schema and rich parameter docs, the description covers the essentials an agent needs: it is a background job, it costs credits, and it requires a wait step. It omits any note on failure modes or what happens if the segment is outside limits, but the core is 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 file paths, resolution tiers, clip length limits and the language enum are already fully documented in the schema. The description adds no parameter-level detail beyond what is there, which is the baseline 3 case.

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 and resource ('Translates speech in a supplied video segment') and scopes it to a segment rather than a whole file. It does not explicitly differentiate itself from the similar sibling add_subtitles_to_video, which keeps it from 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 description names the follow-up step ('returns a project id for wait_for_video_project') and flags that it costs credits, which implies an async workflow. It never says when to choose this over alternatives such as add_subtitles_to_video or edit_video, so usage is only implied.

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