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

The annotations already declare a non-read-only, destructive, idempotent mutation. The description adds useful behavioral context beyond that: only named days are changed, unnamed days are preserved, and booking links plus the day plan follow the new hours. It does not discuss authorization or rate limits, but that is a minor gap given annotation coverage.

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 description is two short sentences with the core scope and side effects front-loaded. Every clause contributes meaning, and there is no redundant or filler wording.

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?

An output schema exists, the input schema is fully documented, and annotations cover safety and idempotency. The description supplies the key behavioral context: which days are affected, what is preserved, and what downstream systems follow the setting. A small gap remains around when to prefer this over related availability tools.

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 the schema already explains days, start, end, and timezone formats. The description adds meaning about the days parameter by stating that unmentioned days keep their existing hours. It does not add any format or usage detail for start, end, or timezone beyond what the schema provides.

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?

The description states a specific verb and resource: setting the user's working hours on named days. It also clarifies the partial-update scope by noting that other days keep theirs. It does not explicitly name or distinguish sibling availability/schedule tools, but the working-hours resource is distinct enough for selection.

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: use this when the user's recurring working hours need to be set. There is no explicit when-not guidance or comparison to related tools such as availability.create or booking_link.update, which could matter when an agent is choosing between schedule changes and one-off availability.

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