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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the full set is returned in a single reply, meaning no pagination or cursor handling is needed, plus the underlying GET endpoint for traceability.

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 sentences, each earning its place: purpose and scope first, then how to consume the output, then the transport detail. No redundancy or filler.

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 zero-parameter, read-only lookup this covers purpose, return cardinality, and downstream use. A slight gap remains in not sketching what each returned record contains (id plus label), which matters somewhat since there is no output schema, but the 'use the ids' phrasing implies it.

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, so the baseline of 4 applies; the description correctly implies no filtering input is accepted by stating all results come back at once. Nothing about parameter semantics is missing.

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 the reasons for non-holiday leave') and immediately scopes it with examples ('compassionate, jury service'), which distinguishes it from sibling leave tools like breathehr_list_leave_requests and breathehr_list_holiday_allowances. An agent can tell this is a reference-data lookup, not a filtered absence query.

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?

It gives downstream usage ('Use the ids to filter absences'), which implies a two-step workflow, but never names an alternative tool or states when this should be skipped. The usage is implied rather than routed.

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