Update a memory

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

Annotations already declare it as non-read-only, destructive, idempotent, and closed-world. The description adds meaningful behavioral detail beyond that: duplicate detection with a named error, and the return shape including 'updated_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-loads the core edit operation in the first sentence, then adds usage guidance, duplicate-refusal behavior, and return information without filler. Every sentence earns its place.

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 mutation tool with no output schema and a rich annotated profile, the description covers the essential missing pieces: when to prefer it over creating a duplicate, duplicate-refusal behavior, and the return shape. Parameter behavior is fully covered by the schema, so nothing critical is absent.

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 100%, so all seven parameters are fully documented in the input schema. The description only lists field names (content, tags, namespace, source, TTL) that the schema already defines, adding no extra syntax or constraints.

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 ('Edit') and resource ('existing memory'), enumerating mutable fields. The sentence about preferring it over storing a second memory distinguishes it from the create-oriented sibling 'remember'.

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 a clear use case—when a fact changes and a second contradicting memory would otherwise be stored—and names the alternative behavior. It lacks explicit when-not guidance, but the condition for choosing this tool is clear.

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