Apply effects to a source

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

Annotations only state readOnlyHint=false and destructiveHint=false, so the description adds useful context like color encoding, example shapes, and format applying to both canvases. However, it does not disclose whether effects are additive or replace existing ones, or the response behavior, which would be valuable 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?

The description is a bit long but front-loaded with the main purpose. The examples are useful and make the nested object semantics clear. Some redundancy exists with 'each an object' repeated, but overall it earns its length.

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?

Given no output schema and complex nested parameters, the description provides enough to call the tool in basic scenarios but lacks details on glow structure, interaction when multiple effects are set, and how effects combine with existing state. It is minimally viable but not comprehensive.

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 0%, so the description must compensate. It explains the effect objects with concrete examples for border, shadow, and blur, and clarifies color format and format scope. It omits detailed structure for glow and does not explain scene_id/source_id, but those are self-evident from schema names.

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 clearly states the tool applies visual effects (border, shadow, glow, blur) to a source. This distinguishes it from sibling tools like set_effect_enabled, which toggles effects, and other set_source_* tools that handle transform, crop, etc.

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 indicates which parameters to provide (any of border, shadow, glow, blur) and notes format behavior, but it does not explicitly state when to use this tool versus alternatives like set_effect_enabled, nor does it mention prerequisites or when not to use it.

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