components_v2_build_container

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds context about the type (17) and the return value being a nestable node, but it does not add richer behavioral detail (e.g., validation behavior or side effects), which is acceptable given the annotations.

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 concise, uses clear labels (Purpose, When to use, Returns), and front-loads the main purpose. Every sentence earns its place with no unnecessary detail.

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 a pure builder tool with good annotations, a complete schema, and an output schema, the description is fully adequate. It explains what it builds, when to use it, and exactly where to use the returned node (inside components_v2_send). No critical gaps remain.

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% and the parameter descriptions are already detailed (e.g., 'Wrap container in spoiler tag', 'Hex RGB integer (0xFF0000 = red)'). The description reinforces the roles of accent_color and components ('accent color + multiple sections/separators') but does not meaningfully add beyond 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?

The description uses a specific verb ('Build'), names the exact resource ('Components V2 Container (type 17) JSON node'), and clearly distinguishes this from siblings like components_v2_build_section and components_v2_build_media_gallery. It also clarifies the output is meant for components_v2_send.

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 'When to use' section provides a clear context: 'compose a card with accent color + multiple sections/separators.' It does not explicitly name alternatives or say when not to use this tool, but the context is specific enough to differentiate from sibling builders.

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