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

Annotations only declare readOnlyHint, so the description carries most of the burden and adds real value: a PII warning ('contains personal data: use small pages'), the 30-requests-per-hour rate limit, the pagination mechanism, and the look-back ceiling. It does not describe error behavior or what fields the certificate/timing blocks contain, keeping it short of a 5.

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?

A single dense block that front-loads scope, then ordering, then the returned fields, then constraints. Every sentence earns its place, though the pacing is compressed and 'oldest first, PAGED by finish time' is slightly redundant.

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 and no annotations beyond read-only, the description compensates well: it enumerates the returned fields, discloses PII and rate-limit constraints, and states the look-back and pagination rules. An agent has everything needed to call it correctly and safely.

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 limit, include_monitor_events, and finished_after_timestamp are already documented in detail. The description reinforces paging direction and 'small pages' but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 (recent finished test results) with explicit scope '(all groups, all exams)', which distinguishes it from the more narrowly scoped siblings recent_group_exam_results and recent_link_results. It also names the backing endpoint GET /v1/groups/recent_results.json.

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?

Provides clear context: oldest-first ordering, paging by finish time, and a 3-month maximum look-back. It stops short of naming the sibling alternatives or stating when to prefer this all-groups scope over an exam- or link-scoped call, so the routing guidance is implied rather than explicit.

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