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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds two genuinely new facts beyond that: results are ordered newest first, and each entry carries its check score. It says nothing about result counts, truncation, or whether larger limits are silently capped.

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 compact fragment with no filler, and the most decision-relevant facts (recency, ordering, optional filter, check score) all appear up front. It reads as a schema annotation rather than a sentence, which slightly weakens the framing but wastes nothing.

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 two-parameter read-only list tool with full safety annotations and no output schema, the description covers the essentials and usefully previews the check score field. It still leaves the agent unable to distinguish test runs from ordinary runs, and gives no sense of result volume beyond the undocumented default of 5.

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 50%: limit is documented in the schema as defaulting to 5 with a maximum of 20, while workflow_id has no schema description at all. The description partially compensates by stating the workflow filter is optional and takes a single workflow, which is the one thing an agent could otherwise misread as a list.

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 description names the resource (test runs) and its scope (recent, newest first, optionally scoped to one workflow), which is enough to pick it over get_test_run or check_test_run. It is a noun phrase with no explicit verb, and it never clarifies how 'test runs' differ from the plain 'runs' in list_runs, so the sibling differentiation is only partial.

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?

'Optionally for one workflow' hints at the filtering case but gives no when-to-use or when-not-to-use guidance. Nothing tells the agent whether to reach for list_runs instead, or whether check_test_run is the deeper per-run follow-up, even though both sit in the sibling catalog.

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