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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the description's 'main read' framing is largely redundant. It adds the backing HTTP endpoint (GET /api/v1/runs) but says nothing about pagination behavior, result volume, or the 100-item page cap, which would have been genuinely useful context.

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 verb and filter set front-loaded, then the usage framing. The trailing 'Trigger.dev: GET /api/v1/runs' is mildly extraneous for an agent choosing a tool, but costs little.

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 read-only list tool with 100% schema coverage and a readOnlyHint annotation, the description covers purpose and filter scope adequately. It does not address pagination or default result behavior, but with no output schema the pageSize/after params in the schema carry most of that burden.

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 all 14 filter parameters are already documented in the schema. The description only groups them ('status, task, tag, queue, schedule or a time window') without adding format or precedence detail beyond what the schema provides, which is the baseline for full coverage.

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?

States a specific verb+resource ('List task runs') and enumerates the filtering dimensions, so an agent immediately knows this is the bulk read over runs. It stops short of naming the contrasting siblings (trigger_get_run for a single run, trigger_list_run_events for event-level detail), so it is clear but not fully differentiated.

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 line 'This is the main read for "what ran, and what failed?"' gives clear situational context for choosing this tool. There are no explicit exclusions or named alternatives (e.g. when to prefer trigger_get_run or trigger_list_run_events instead), so it never reaches a 5.

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