Append Capacities content

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

Annotations already indicate non-read-only, non-idempotent, and non-destructive behavior. The description adds that it appends structural blocks and mentions placement options, but it does not disclose side effects, error conditions, or consequences of appending (e.g., whether blocks are inserted or duplicated). This is adequate but not extensive.

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 single, focused sentence that front-loads the verb and resource. It clearly conveys the tool's purpose without unnecessary words or repetition of schema details.

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 the complex schema and output schema presence, the description is sufficiently complete. It captures the core action and key options, while the schema covers parameter details. No major contextual gaps are evident, though it could mention interaction with existing content or prerequisites.

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 parameters are already well-documented. The description's mention of placement options (start, after a block, etc.) mirrors the schema's position enum and property descriptions without adding new semantic value beyond what the schema provides.

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 action ('Append'), the resource ('structural API 2.0 blocks to an existing object'), and the placement options (start, after a known block, inside a parent block, or in a specific block property). This differentiates it from siblings like append_content_markdown, which handles markdown content.

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 implies usage for structured blocks but does not explicitly state when to use this tool over alternatives like append_content_markdown or when not to use it. Sibling names hint at the distinction, but the description itself lacks explicit guidance or exclusions.

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