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

Annotations already declare readOnly, idempotent, non-destructive and non-open-world, so the safety profile is covered. The description adds real, non-obvious behavior — that same repo/job names may merge workflows and that results carry no samples, minimums or exemplar IDs — but the phrasing is cryptic and omits limits or aggregation granularity.

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?

Two short sentences with no filler and the purpose front-loaded. It is terse to the point of under-specification, but nothing is wasted.

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, so return values need not be explained, but for a filtered analytics tool with two nullable parameters and no parameter documentation, the description leaves too much to inference: no usage context, no filter semantics, no indication of aggregation granularity.

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% at the property level, and the description says nothing about 'window' or 'filters'. Only the nested $defs carry semantics (half-open UTC window, maxItems caps), so the description fails to compensate for the coverage gap.

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 verb+resource is present ('Read job/step duration groups'), so an agent knows this is a read-oriented analytics call. However, 'duration groups' is ambiguous (grouped by what?) and nothing distinguishes it from close siblings like 9apes_get_run_stats, 9apes_rank_jobs or 9apes_compare_windows.

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?

There is no statement of when to use this tool, when not to, or which sibling to pick instead — despite eight sibling tools that overlap heavily in the analytics space. The second sentence is a data caveat, not usage guidance.

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