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

Goes well beyond the annotations: it discloses the ~1 minute wait with longer jobs continuing asynchronously (visible in backup_list), that the call consumes the owner's storage quota, and that retention removes the oldest archive once the 'keep last' count is reached — a destructive side effect the annotations only flag generically. The prerequisite/error path is also described.

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?

The core action is front-loaded in the first clause, followed by timing, prerequisites, and retention — all information that earns its place. Minor waste in re-explaining what the 'label' parameter is for, which the schema already covers.

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?

With no output schema, the description still explains what happens during and after the call (waits, or keeps running and appears in backup_list) and the failure mode when no backup job exists. Things like the returned job/archive identifier or behavior for an unknown host are unstated, but for a 3-param tool with full annotation coverage this is close to complete.

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 all three parameters are already documented, including the same 'job defaults to the first' and 'label = why' hints. The description restates the label guidance rather than adding new meaning (format, length limits, behavior when job name doesn't match), so 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?

States a specific verb and resource ('Make an encrypted backup of one of the user's servers now') and names the mechanism ('through Termalin's backup job for that server'). It also implicitly distinguishes itself from backup_list by pointing there for long-running jobs, so an agent can separate it from the sibling list tool without opening schemas.

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 trigger ('Call it BEFORE a risky change — a migration, a config rewrite, a bulk delete') and a stated prerequisite (a backup job must exist in the Termalin cabinet, otherwise the tool explains how to add one). It also routes the agent to backup_list for jobs that exceed the wait window, which is the relevant alternative.

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