updates_policy

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

With no annotations, the description carries the full behavioral burden and does well: it discloses which files are written, which timers are enabled, and the deliberate no-reboot policy. It does not disclose privilege requirements, idempotency, or reversal behavior when the policy is later changed, leaving a modest gap for a write-configuration tool.

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 dense sentences, front-loaded with the core policy outcome before the implementation files. Every clause (auto-install scope, no-reboot rule, written paths, apt-only boundary) carries distinct, non-redundant information.

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 six-parameter mutation tool with no annotations and no output schema, the description covers the essential policy semantics and scope boundary, while the schema handles apply/planHash mechanics. It omits any note on required privileges or effect on hosts already carrying a conflicting policy, which would round it out.

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 100%, so all six parameters (apply, batch, target, planHash, continueOnError, skipUnreachable) are already documented in the schema, including the dry-run/planHash workflow. The description adds no parameter-level syntax or format detail beyond what the schema provides, so the 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+resource (bring hosts to the fleet update policy) and enumerates the exact configuration outcome: security-only unattended upgrades, no auto reboots, which files are written (/etc/apt/apt.conf.d/20auto-upgrades and 99zz-mia-policy). An agent can distinguish this from apt_upgrade (which performs upgrades) and host_reboot (which it explicitly routes reboots to) without opening any 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?

Names the alternative for the excluded behavior ('reboots stay manual (host_reboot)') and gives an explicit applicability boundary ('apt-based hosts only'), which tells the agent when this tool is valid. It stops short of stating when to prefer this over apt_upgrade or tuning_apply, so it is strong context without full when/when-not coverage.

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