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

No annotations are present, so the description carries the full burden of explaining behavior. It discloses that the tool fetches neighboring turns and recovers nearby facts without indicating state mutation. While it doesn't explicitly state read-only or discuss rate limits/pagination, the fetch/expand framing strongly implies a non-destructive retrieval operation.

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 two sentences, front-loaded with a clear summary, and enhanced with concrete examples that add value without waste. It is concise and every sentence contributes to understanding the tool's purpose.

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 tool with three parameters and an output schema, the description covers the core use case and behavior well. However, it omits any explanation of the `mode` enum and leaves the exact role of `hit_ids` implicit. This is a notable gap, though the presence of an output schema reduces the need to describe return values.

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 0% and the description only hints at the radius_turns parameter via '±N turns'. The mode parameter (turn/session/window) is completely unexplained, and hit_ids semantics are only weakly implied by 'promising retrieval hits'. The description does not adequately compensate for the schema's lack of parameter descriptions.

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?

Description uses a specific verb ('fetch') and resource ('±N turns from the same session'), clearly distinguishing it from generic context retrieval. Concrete examples like 'my parents' and 'Disney+' make the purpose vivid and actionable. It is not a tautology and stands apart from sibling tools like get_relevant_context.

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?

Provides an explicit conditional: 'When you find a relevant chunk but the specific fact is in a nearby turn, use this'. This is clear context for when to invoke the tool. However, it does not mention when not to use it or name alternative tools, so it falls short of a full 5.

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