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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely new behavior: expired entries are filtered out, ordering is priority then most-recent-first, and unknown/empty sessions return [] rather than erroring. Only gap is that it restates 'Read-only' which annotations already provide.

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?

Front-loaded with purpose, then return shape, then usage, then args — a sensible order. Slightly redundant in restating 'Read-only' after the annotations and in the multi-line arg block, but no sentence is wasted at the level of content.

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?

No output schema exists, and the description compensates by describing the returned fields, expiry filtering, ordering, and the empty-result case. Combined with the usage routing and the session_id disambiguation, an agent has everything needed to call this correctly on the first try.

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 only parameter is undocumented in the schema, so the description must carry it — and it does: session_id is the application-level NEXUS id used with push_context, explicitly NOT the MCP transport session. That disambiguation is exactly the failure mode an agent would otherwise hit.

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?

States a specific verb and resource ('Read a session's working memory') and immediately defines the resource as the short-lived key/value entries written by push_context. That definition, plus the explicit contrast with durable knowledge in retrieve_memories/cognitive_query, separates it cleanly from the many memory-related siblings.

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 positive case ('recover scratch state within the same piece of work, e.g. what you were in the middle of'), explicit negative case (durable knowledge is not here; use retrieve_memories or cognitive_query), and a routing note that retrieve_memories also returns these entries with the same session_id. When-to-use, when-not, and alternatives are all present.

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