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

With no annotations, the description carries the safety and behavioral burden. It does disclose that this is a mutating operation and that each write incurs a charge, which is useful context. It leaves unspecified whether writes with an existing key overwrite memory, what permissions are needed, and what response or side effects occur.

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 with no filler. The action and destination are front-loaded, and the cost warning is a distinct second sentence that 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 tool with five undeclared parameters, no annotations, and no output schema, this is under-specified. It leaves out key behavior, author semantics, embedding semantics, return values, and what 'space' means in the API context, so an agent is not fully equipped to call it correctly.

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 0%, so the description must compensate. The phrase 'note into a space' gives some meaning to content and spaceId, but required author is unexplained and optional key/embedding are not mentioned at all. The description does not add enough to make the five parameters safely usable.

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 uses a specific action and target: 'Write a note into a space.' It clearly identifies the tool as a write operation for memory notes. It does not explicitly contrast itself with siblings like search_memory or store_file, so it stops short of full differentiation.

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?

No guidance is given about when to prefer this tool over search_memory, memory_prices, store_file, or other storage-related tools. 'Charged per write' hints at a cost consideration but does not state prerequisites, exclusions, or alternative selection criteria.

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