Next shift

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered; the description adds a real capability boundary ('other people's shifts are not available in this mode') and the return shapes (markdown note vs single Roster record or null). It stops short of saying what actually happens if a non-empty 'employee' is supplied — error, silent ignore, or fallback — which is the one behavioral unknown.

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?

Three short blocks — purpose, when-not, return shape — with the scoping constraint front-loaded. No filler sentences and no repetition of the annotations or schema.

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 and annotations cover read-only behavior, so the description is not obligated to explain return values, yet it does so concisely (markdown / Roster record / null). The only gap is the undefined behavior when 'employee' is populated, which matters for a tool whose whole design hinges on that field being empty.

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 the baseline is 3, but the description adds meaning the schema does not: the 'employee' field is documented as 'Employee name or id' yet the description tells the caller to leave it empty and explains why (other people's shifts are unavailable). That is genuinely corrective guidance rather than a restatement.

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 ('Return your own next upcoming shift') plus the data source ('personal Deputy calendar feed'), which is enough to distinguish it from deputy_get_my_roster and deputy_get_my_calendar_url. The scope word 'next' and 'own' are the discriminating qualifiers an agent needs.

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?

Explicitly names the when-not case ('for a range of shifts') and routes to the specific sibling to use instead (deputy_get_my_roster). It also tells the agent how to call it correctly by instructing to leave 'employee' empty.

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