memory_list_sessions

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

With no annotations, the description carries the full behavioral burden. It does disclose the return envelope (session_count plus sessions with memory counts and previews) and hints at an expensive multi-probe vector scan, but it never states that the operation is read-only/non-destructive, says nothing about collection scoping requirements, latency or cost, or what happens when the collection is empty or missing.

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?

Three short sentences, front-loaded with the outcome (what you get) before the mechanism and return shape. The phrase "multi-probe vector queries" is implementation jargon that contributes little for an agent, a minor waste.

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 read tool with no annotations or output schema, the description covers purpose and return shape adequately, so an agent can call it and interpret the result. The remaining gap is behavioral — cost/safety context — which matters less for a low-risk enumeration call.

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% for the single `limit` parameter, so the schema already defines it as the max candidate memories scanned across domain probes. The description adds no meaning beyond that — notably it never connects `limit` to the trade-off between scan breadth and discovery completeness, which would have been genuinely useful here.

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 gives a specific verb ("Discover") and resource ("unique session_ids and active conversation threads") scoped to a named collection, so an agent immediately knows this enumerates sessions rather than memories. It does not explicitly contrast itself with siblings like memory_stats or memory_recall, which keeps it from a 5.

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?

There is no statement of when to call this versus memory_recall, memory_stats, or memory_explore_hierarchy, and no prerequisites or exclusions. The agent must infer that this is a pre-step for session-scoped recall purely from the tool name.

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