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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description adds real value beyond that with the newest-start-first ordering, the note that closed rows carry a typed end reason, and the warning that one person may hold several rows. It does not mention pagination behavior, though limit/offset exist in the schema.

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 sentences, front-loaded with the core identity before filters and caveats, with no filler. The density is high but each sentence contributes distinct information; the em-dash asides are slightly heavy but 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?

With no output schema, the description compensates by describing what each row carries (person, position title, shop, manager, dates, end reason) and by flagging the multi-row-per-person pitfall. That is close to complete for a filtered list tool; only paging/result-size behavior is unaddressed.

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 0%, so the description must carry the load, and it does: it enumerates the status values (active/probation/suspended/leaving/ended), gives examples for kind, and explains open_only as 'periods with no end date, i.e. the current staff'. Only limit/offset are left unexplained, which is acceptable for standard paging parameters.

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?

Opens with a specific framing ('Who WORKS here — the employment periods, newest start first') that names the resource, the ordering, and implicitly separates it from hr_list_people. An agent can tell this lists employment periods rather than people or vacancies 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?

Explicitly states it is read-only and that the 'engagement_id' consumed by hr_close_engagement and hr_update_engagement originates here, which is genuine routing guidance. It lacks an explicit 'use X instead when...' exclusion, but the 'Who WORKS here' framing plus the write-tool dependency covers most selection needs.

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