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

Annotations already declare write (readOnlyHint=false), idempotentHint=true, destructiveHint=false and closed-world, so the safety profile is covered. The description adds real value by disclosing the toolbox-creation side effect, the returned key, and the ongoing "warns you if it gets worse" monitoring. It does not say what happens on a duplicate save, any toolbox size limit, or how the key is protected.

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 front-loaded sentences plus a compact example; the first-use rule is stated before the illustration and nothing is redundant.

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?

Covers the create-on-first-save flow, the key return, and the monitoring promise for a 4-param tool with full schema coverage and annotations. Missing details are duplicate-save behavior and any limits, though no output schema exists to explain the return payload.

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 100%, so the baseline is 3, but the description adds a concrete tool_id format example ("page.doc/pdf-extract") and reiterates the omit-key-on-first-use lifecycle in the context of the save flow. The name and note params are left entirely to the schema.

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 and resource ("Save a tool ... in your private toolbox") plus the added effect that Faceabot monitors it. An agent can readily tell this apart from remove_tool_from_toolbox and list_my_toolbox by the verb alone.

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 an explicit procedural rule: the first save must omit the key, which creates the toolbox and returns the key. It does not state when to prefer this over adjacent tools like save_memory_note or when not to save, so no true alternatives guidance.

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