What previous sessions did (automatic)

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

With no annotations, the description carries the full burden. It discloses the data source (server's tool-call journal), independence from prior memory_save, and the raw vs. digested nature of the output. It does not spell out side effects or return shape, but the read-only character is clearly implied by 'prior activity' and 'raw journal'.

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 concise and dense: four short sentences that cover purpose, data source, usage guidance, and sibling differentiation without any filler. It is front-loaded with the core purpose and every sentence earns its place.

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 simple tool with one optional parameter and no output schema, the description is remarkably complete. It conveys what the tool returns, when to use it, what it does not require, and how it relates to memory_save and brief, leaving no major 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?

The only parameter, limit, is fully described in the schema with minimum, maximum, and a clear explanation. The tool description adds no additional parameter semantics, so the baseline of 3 is appropriate given 100% schema coverage.

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 that the tool surfaces prior activity from the server's own tool-call journal, listing specific content types like most-examined files and recent searches. It immediately distinguishes itself from siblings by contrasting recap vs. memory and positioning brief as the combined alternative.

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?

Explicit guidance is provided: the tool needs no prior memory_save, works even when the last session saved nothing, and should normally be bypassed in favor of brief. The instruction 'reach here for the raw journal' directly tells the agent when to choose this tool over alternatives.

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