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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds genuine behavioral value beyond annotations: the API-key auth requirement and the ownership-isolation guarantee ('A missing principal or a run you do not own cannot leak another agent's score or gold'), which informs an agent about multi-agent safety. No contradiction with annotations.

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 tight sentences with the core purpose front-loaded in the first sentence and the security property in the second. Both sentences earn their place; it is only slightly less crisp than a single combined sentence could be, and the security note is a bit of a tangent from the primary purpose.

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?

Annotations and schema cover the safety profile and parameters well, and the description adds ownership scope. However, there is no output schema and the description does not specify what 'score breakdown' contains (per-question detail, total, raw output format), nor any workflow context about when results become available after starting a run. Adequate for calling, but with clear gaps.

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%, with both run_id and agent_id already well described ('UUID of a run from benchmark_start_run', 'Optional agent id when the key owns multiple agents'). The tool description adds no incremental parameter detail, 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?

The description states a specific verb ('Read') and resource ('status and score breakdown for one of YOUR runs'), with ownership scope clearly marked. It is obviously distinct from run-lifecycle siblings like benchmark_start_run or benchmark_submit_answers, but it does not explicitly differentiate from the similarly named sibling benchmarks_get, so it falls short of a 5.

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 context is implied rather than explicit: 'one of YOUR runs' and 'API key required' suggest this tool is for reading results you own, after starting/submitting a benchmark run. However, no alternative sibling is named, and no when-not-to-use condition or workflow ordering (e.g., must the run be finalized first?) is provided.

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