List schedules

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds substantive behavioral context beyond them: it guarantees an explicit error instead of an empty list on read failure, and insists that 'no window configured' and 'could not read' be distinguishable. That failure-mode contract is exactly what a caller deciding on a reboot needs.

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 sentences, front-loaded with the purpose and return fields before the error-behavior caveat. The second sentence is dense and slightly repetitive in restating the 'no window' vs 'could not read' distinction, but the content is not wasteful.

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, so the description carries the return-value burden itself and does so by naming the fields returned. Combined with the explicit error semantics, an agent has everything needed to call the tool and interpret its outcomes.

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 zero parameters and schema coverage is 100%, so there is nothing for the description to compensate for; baseline 4 applies. The description correctly adds no redundant parameter discussion.

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 ('List router schedules'), gives a concrete example (firmware auto-update window), and enumerates the returned fields (name, weekday/time actions, seconds until next fire). An agent can distinguish this from siblings like reboot or get_config without opening the 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?

Usage is implied rather than stated: the closing clause frames the tool as something 'a caller deciding whether it may reboot the router' consults, which hints at the reboot relationship. However, no alternative is named and no explicit when-to-use/when-not guidance is given.

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