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

Goes well beyond the annotations: TTL cap of 30 days, cross-region read lag up to a minute, 404-on-miss/expired with no charge, and per-call pricing with 25 free. The note that every call is charged even if repeated directly explains why idempotentHint is false for a read-only tool — genuinely useful context an agent cannot get from structured fields.

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 the action and scoping, then cost/lag caveats, which is the right order. Slightly over-packed: 'failed calls free' duplicates the earlier 'is not charged', and 'changes nothing' restates readOnlyHint, costing a little density.

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 only two required params and no output schema, the description covers everything an agent needs: how to address the record, what comes back (value plus saved and expiry timestamps), failure mode, staleness window, and cost. Nothing material is left to guess.

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%, so baseline is 3, but the description adds a worked example (namespace=demo-agent-memory-7f3c9a21, key=user-preferences) that illustrates the expected shapes and reinforces that key is scoped inside namespace. Minor value-add only, since the schema already spells out both fields.

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+resource (read a saved value by namespace+key) and ties it explicitly to its counterpart /memory/set, so the read/write pair with memory_set is unambiguous. The one-line 'Use to recall what an agent saved in an earlier run' pins the intent with no vagueness.

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?

Gives clear situational context ('recall what an agent saved in an earlier run') and a concrete example call with namespace and key. It does not explicitly exclude or route to siblings like memory_list or memory_delete, so an agent must infer when listing beats direct key lookup.

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