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

With no annotations, the description carries the full burden and delivers real behavioral context: durability across restarts, account-wide sharing, namespace defaulting, and concrete quotas (100 MB, 100k items, 256 KB values, 4 MB files). It omits auth requirements and the destructive consequences of delete/file_delete, keeping it from 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?

Front-loaded with the core identity before the action list and quotas, with no filler sentences. It is dense and long, but every clause maps to a real action or parameter, so the length is justified by the tool's complexity.

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 13-parameter, no-annotation, no-output-schema tool, the description covers actions, key parameters, namespacing, and limits well. It stops short of describing return shapes per action, which is a minor gap given no output schema exists.

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 0% across 13 params, so the description must compensate — and it largely does, documenting value/ttl_seconds/if_version (compare-and-set), by, prefix/after/limit, name/content_base64/content_type, and the ns default. Only key and action are left to the schema, so coverage is strong though not exhaustive.

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 resource (durable key-value + file storage for the bot) and enumerates every action, so an agent knows exactly what it is. It does not explicitly distinguish itself from storage-adjacent siblings like vault, secrets, or memory_*, so it falls short of a 5.

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?

The description lists actions but never says when to reach for this tool over alternatives such as memory_save_checkpoint or vault. The 'survives sandbox restarts' line hints at persistence scope, but there is no explicit when/when-not guidance or named alternative.

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