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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact — 'Commits immediately' means no confirmation step — but says nothing about deduplication, overwriting an existing fact, or how visibility defaults affect who can recall it.

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?

Two short sentences, front-loaded with what the tool does and followed immediately by the commit behavior. Nothing is wasted or padding.

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 5-parameter mutation tool with privacy-relevant enum defaults and no output schema, the description is too thin. It never explains how memory_type/sensitivity/visibility should be chosen or what happens to a previously stored conflicting fact, which is exactly the guidance an agent needs here.

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 only 20% (just 'content'), leaving confidence, visibility, memory_type and sensitivity undocumented in both schema and description. The description adds no meaning for these, which is a real gap because the default visibility of 'shared_household' and the sensitivity enum carry privacy consequences an agent must reason about.

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 ('Save a durable fact/preference') plus the purpose ('for future recall'), which cleanly separates it from forget_memory and the task/event creation siblings. It does not explicitly name an alternative, but the resource type is distinctive enough for an agent to select it.

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?

Usage is only implied: 'the user stated' hints at the trigger condition and 'durable' hints at an exclusion, but no explicit when-to-use/when-not or reference to alternatives like forget_memory is given. The word 'durable' also sits awkwardly with the schema's temporary_session/temporary_context options.

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