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

Annotations already establish that this is a non-destructive, non-idempotent write (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds genuinely useful behavior beyond that: earlier content and history are preserved, and an update identical to the latest is skipped. It stops short of covering permissions or what happens on conflicts.

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 core action and preservation behavior, then the dedup rule, then the usage cue. No filler and every clause carries information.

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 14-parameter tool with nested objects, 29% schema coverage, and no output schema, this description is far too thin. It omits any explanation of the many advanced parameters (force, trust, supersedes*, contradictionAck) that an agent would need to call the tool beyond its minimal two required fields.

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 only 29% across 14 parameters, so the description is expected to compensate but does not. Undocumented fields such as force, trust, supersedesBody, supersedesLayer, contradictionAck, and section are left entirely unexplained, and only 'dated' loosely gestures at observedAt.

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+resource ('adds a dated update layer to an existing memory') and its non-destructive nature ('keeping its earlier content and history'), which implicitly separates it from the replace-style memory_upsert. It does not name a sibling explicitly, but the append-layer framing is distinct enough for an agent to choose correctly.

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?

'Use for new developments on something already saved' gives implied when-to-use context. However, it never names the closest alternative (memory_upsert) or states any when-not condition, so the agent must infer the append-vs-upsert boundary from semantics alone.

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