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

Annotations already establish this is a non-read-only, non-idempotent, non-destructive write, and the description usefully explains why it is non-idempotent ("Each call adds a new memory") and adds a hard size constraint (500 chars). It does not cover what happens on failure or whether memories can be duplicated or capped, so it stops short of a 5.

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?

Four short sentences, front-loaded with the definition before the constraints and exclusions; the only mild repetition is the 500-character limit, which is reasonable to surface in prose because it is a hard authoring constraint.

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 two-parameter creation tool with no output schema and full schema coverage, the description supplies everything an agent needs: what a memory is, required size limit, scoping choice, and the routing rules to the two nearest alternatives.

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% and both parameters are already documented there, including that workspace_id is a UUID from list_workspaces and that omitting it yields a personal memory. The description restates the personal-vs-workspace distinction but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 opens with a specific verb and resource ("Save a memory") and immediately defines what a memory is ("a short fact ISMS Copilot uses as background in later answers") plus its two scoping modes. It also names the sibling it is not — update_memory and set_company_context — so an agent can distinguish it from siblings without opening a schema.

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?

It gives an explicit positive trigger ("only when the user asks ISMS Copilot to remember something") and two explicit exclusions with the correct alternative named for each (set_company_context for company facts, update_memory for edits). Nothing is left to inference about when to route elsewhere.

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