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

Annotations declare destructiveHint=true with openWorldHint=false, so the agent knows this writes files in a closed local scope. The description adds the canvas/aspect constraint but does not warn about overwriting existing output paths or that the operation is non-idempotent, which is exactly the behavior the destructive flag is pointing at.

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?

One well-formed sentence, front-loaded with the verb and the tool's value proposition, with the optional canvas variants trailing. Every clause maps to a parameter or capability; nothing is wasted.

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?

An output schema exists and all parameters are documented, so the description only needs to convey core behavior, which it does. It falls slightly short on when-to-use guidance and file-writing/overwrite semantics, but for an 11-param tool with a fully documented schema this is close to sufficient.

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 every parameter is already documented, including enum values and defaults. The description restates the treatments (padding, rounded corners, drop shadow, gradient) but adds no syntax or precedence detail (e.g., how colors vs. image vs. preset interact) beyond the schema, making a baseline 3 correct.

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 opens with a specific verb ('Frame') applied to a specific resource (video or screenshot) and enumerates the distinct visual treatments (gradient, color, wallpaper; padding, rounding, shadow, canvas aspect). No sibling tool (overlay, callout, title_card, reframe) offers this composite framing behavior, so an agent can distinguish it at a glance.

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?

It implies usage ('Frame a video or screenshot') and lists the canvas options, but never states when to pick this over reframe, overlay, or title_card, nor any prerequisites or exclusions. The context is inferred rather than spelled out.

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