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

Annotations already declare non-read-only, non-destructive, non-idempotent, so the safety profile is covered. The description adds real context beyond them: the tool stops at idea generation rather than producing slides, and it emits an idea_id that another tool consumes. It omits processing characteristics (time, limits beyond the schema, what happens on unsupported URLs), which keeps it below 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?

Two short sentences with no filler; the input forms and the output contract are both front-loaded. Every clause carries information an agent needs to select and chain the tool.

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 discloses the return value (idea_id) and its consumer, and it clarifies that no slides are produced. For a non-idempotent processing tool it could say more about failure modes or processing expectations, but nothing essential to correct invocation 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 adds value by grouping the three video sources (link, base64 file, upload_id) into a single 'choose one of these' signal that the flat schema does not convey. It does not spell out mutual exclusivity or defaults for mode/lang, which remain schema-only.

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 ('watch a video ... turn it into a carousel idea') and enumerates the three accepted input forms. It also names the downstream consumer of the returned idea_id (build_carousel), which helps distinguish it from siblings. It does not differentiate from create_carousel_from_video, which reads like a near-neighbour.

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 phrase '(no slides yet)' plus 'Returns an idea_id that build_carousel accepts' establishes where this tool sits in the pipeline and what the next step is. There is no explicit 'use X instead when...' guidance against create_carousel_from_video, so the routing edge case is left to inference.

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