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

With no annotations provided, the description carries the behavioral transparency burden. It discloses the row granularity, the returned fields (id, status, totals, timestamps, durationMs), and the authenticated-user filter. It does not discuss failure modes or side-effect guarantees, but 'List' strongly implies a read-only operation.

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 three sentences with no filler. The main action, output shape, and use cases are all front-loaded, and every sentence contributes useful information.

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 listing tool with no output schema, the description is largely complete: it describes what is returned, why it is useful, and that results are scoped to the authenticated user. It could go slightly further by clarifying how this relates to replay summary/status siblings, but nothing essential for calling it is missing.

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 the input schema already documents recordingId and limit, including the default and ordering. The description adds little parameter-level meaning beyond referring to 'a saved recording,' so the baseline score of 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 opens with a clear verb and resource: 'List all replay runs of a saved recording — the run history.' It also enumerates the concrete output fields, making the tool's purpose unambiguous and distinguishing it from singular replay actions like flow_replay_status or flow_recording_replay.

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?

The description gives explicit use cases: 'trend analysis (pass rate over time)' and 'finding the most recent failure to drill into.' It does not name alternatives or exclusion criteria, but the context is clear enough for an agent to decide when this historical listing tool is appropriate.

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