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

With no annotations, the description carries the full behavioral burden. 'Check' signals a read-only operation and the description usefully discloses two return fields (running status and issue count), but it omits error behavior, authentication needs, and whether any other run details are returned.

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?

The description is a single efficient sentence that front-loads the core purpose and immediately specifies the two pieces of information returned. No sentence 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?

For a simple one-parameter read tool with no output schema, the description is nearly complete: it explains what the tool checks and what it returns. The only notable gap is behavior on errors or missing run IDs, but the core agent need is covered.

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% for the single parameter, and the schema itself explains that testRunId is the run _id returned by start_test_run. The description adds no additional parameter semantics beyond the schema, so the baseline 3 is appropriate.

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 states a specific verb ('Check') and resource ('a test run'), plus the exact information returned: running state and issue count. It does not explicitly differentiate itself from siblings like start_test_run or stop_test_run, though the read-oriented phrasing helps.

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?

Usage is implied: an agent can infer this is for checking an existing run's status rather than starting or stopping one. However, there is no explicit when-to-use guidance, no mention of alternatives such as list_issues for issue details, and no prerequisites like needing a testRunId from start_test_run.

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