Are.na block

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

With no annotations provided, the description carries the full burden. It does convey a read-only lookup and discloses that the result includes the block's details plus its channels. It does not mention error behavior, authentication needs, or what happens when a block id is invalid or has no channels.

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, front-loaded sentence with no wasted words. It states the resource, the lookup mechanism, content types, and the additional channels payload efficiently.

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 one-parameter tool with no output schema, the description adequately explains what the response will contain: block details and associated channels. It could mention auth or error handling, but the low complexity and clear return scope keep it reasonably complete.

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 only parameter, id, is already described as a numeric block id. The description adds little beyond restating that lookup is by id, so the schema does the necessary work.

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 names the specific resource (a single block), distinguishes among content types (image/link/text), identifies the lookup key (by id), and notes the extra output (channels). It is easily differentiated from siblings like arena_channel_contents or arena_channel, which target channel-level data.

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?

Usage is implied by 'by id': an agent should call this when it has a specific block id and wants that block's details. However, there is no explicit guidance about when to prefer this over arena_channel_contents or arena_search, and no exclusions are stated.

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