list_history_days

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

Annotations already declare readOnly, idempotent and non-destructive, yet the description still adds genuinely new behavioral context: sampling cadence of every 10 seconds, retention of 7 days by default, a configurable 1-to-90 range from Settings, and an empty result when history is disabled. That is real information an agent cannot get from the annotations or the empty schema.

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 action in the first sentence, then layers the retention/availability caveats and finally the call-order instruction. The clause about Anabolic recording in the notification area is background flavor that could be trimmed, but the whole thing remains compact and skimmable.

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?

There is no output schema, but the description names the fields each day carries (date and size on disk), covers the empty-result case, and gives the sequencing rule. For a zero-parameter read tool, nothing an agent needs in order to call it correctly is missing.

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?

The tool takes no parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description does clarify what the returned entries contain, which is a small bonus.

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 ("Lists the days the history holds") and names the payload of each entry ("date and size on disk"). It also positions itself against the sibling get_history by saying the list exists "to pick one for get_history", so an agent can tell the two apart 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?

Gives an explicit call ordering ("Call it first when the user asks about an earlier time") and implicitly routes to get_history as the follow-up. It also warns that the list is empty when history is turned off. It stops short of stating when not to use it, e.g. when the user asks about the present moment.

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