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

The annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), and the description adds genuinely new behavioral facts: a 256 KiB per-value cap, an optional ttlSeconds, the requirement for an approved workspace key, and plan-dependent quota (5 MiB on Free). The main omission is the overwrite/upsert semantics when a key already exists, and what happens on TTL expiry.

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?

A single dense sentence cluster that front-loads the core action and example before moving to limits and auth. Nearly every clause carries information an agent would otherwise lack; only the plan/Free-tier detail is slightly tangential.

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 4-parameter write tool with full annotations and no output schema, the description covers the key operational facts an agent needs: auth prerequisite, size limit, quota, and TTL option. Remaining gaps are limited to overwrite semantics and post-write return behavior, which are minor given the rich annotation set.

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 75%; namespace and key constraints are already documented in the schema, and the description's example adds a little orientation but nothing new about formats. The one undocumented parameter, ttlSeconds, is merely called 'optional' with no units confirmation, range, or expiry behavior, so the description only partially compensates for the gap.

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 states a specific verb and resource: persist a JSON value under a namespace/key pair for later sessions, and gives a concrete namespace/key example. It is clearly distinct from siblings like memory_get, memory_list, and memory_delete by implication of the name and 'remember' framing, though it never names those alternatives explicitly.

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?

'for later sessions' implies this is for cross-session persistence, which is useful context for when to reach for it. However, there is no explicit when-not guidance, no mention of when to prefer memory_get/memory_list for reading, and no note on what happens when the key already exists.

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