fetch_history

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 behavioral disclosure. It communicates that the tool returns historical memories in chronological order and supports pagination, but it does not explicitly state that this is a read-only operation free of side effects, nor does it mention error behavior for unsupported memory types. The schema covers some of these details, but the description itself lacks explicit safety/reversibility language.

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 and front-loaded with the primary action, but it repeats 'timeline review' twice ('Useful for chronological timeline review' and 'primary tool for timeline review'), which is slightly redundant. Despite that, it is concise and efficiently communicates the tool's purpose and usage.

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?

With 8 parameters, no output schema, and no annotations, the description provides clear usage context and differentiates the tool from recall. It covers the main use cases but doesn't explicitly describe the return format or pagination behavior details, although the schema already describes limit/offset and memory_type constraints. Overall, the description is sufficiently complete for an agent to select and invoke the tool correctly.

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%, with each parameter already having a detailed description. The tool description adds little beyond restating 'memory_type' and 'space' and provides no additional context that is not already in the schema. A baseline score of 3 is appropriate because the description does not need to compensate for schema gaps.

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 ('Page through historical memories') and the resource ('in a space by memory_type'), and it distinguishes this tool from recall by framing it as a chronological timeline review versus relevance ranking. It also explicitly names the tool as the primary choice for timeline review, pre-delete verification, and post-delete re-checks.

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 explicitly provides when to use this tool ('when recall's relevance ranking is not sufficient' and 'when you need to browse all memories of a type') and lists the main use cases. It implies an alternative (recall) and gives context for choosing fetch_history over other siblings.

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