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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, establishing the safety and idempotence profile. The description adds the typical use case (output of a prior Actor run) and an example, but does not disclose additional behavioral details such as pagination limits, potential rate limits, or the exact structure of returned items. With annotations covering the core safety traits, this is adequate but not rich.

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, concise sentence with a practical example that illustrates usage. The purpose is front-loaded and there is no filler. It could potentially be structured with more detail, but it remains efficient and clear.

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 read-only tool with five parameters, all documented in the schema, and no output schema, the description is functional but could be more complete. It does not mention anything about the return format, pagination behavior, or error handling, though annotations cover the safety profile. The description is adequate for basic invocation but leaves some contextual gaps.

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 all parameters are documented in the schema. The description's example highlights datasetId and limit, but adds no additional semantic nuance beyond what the schema already provides. The baseline of 3 is appropriate given the schema fully covers parameter meaning.

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 states a specific verb ('Fetch') and resource ('items from an existing Apify dataset'), and includes a concrete example invocation. It does not explicitly contrast with sibling tools like apify_run_actor or apify_scrape_url, but the mention of 'output of a prior Actor run' clearly indicates its role. This is clear and distinct enough for an agent to recognize the tool's purpose.

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 provides minimal context about when to use it (after an Actor run) but gives no explicit guidance on when not to use it or which sibling tool to prefer in other scenarios. It does not mention alternatives or exclusions, leaving the agent to infer the appropriate context on its own.

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