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

Annotations already declare readOnlyHint=true, destructiveHint=false and a closed world, so the safety profile is covered. The description adds two non-obvious behaviors beyond that: results are sorted by most recent update, and setting ended_after silently drops rows lacking ended_at. It does not disclose the default status filter (terminal states only), which materially changes what comes back, nor any pagination behavior despite a cursor parameter.

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 sentences with zero padding; the resource and ordering come first, and the filter caveat follows. Every clause carries information an agent would otherwise have to guess.

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?

With no output schema, 0% schema description coverage, and six parameters including a cursor, the description leaves too much unexplained: pagination, how limit interacts with cursor, and what the results/statuses filters accept. It covers ordering and one filter well but is not complete enough to invoke confidently beyond the simplest call.

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 0% across six parameters, so the schema names fields without explaining them. The description compensates for ended_after well (timestamp semantics plus the null-exclusion side effect) and hints at project_id via 'project-scoped', but limit, cursor, results and statuses receive no explanation at all, including the consequential default status set.

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 a specific verb and resource ('List project-scoped experiment outcomes and learnings') plus the ordering rule ('newest update first'), so an agent knows exactly what it returns. It never contrasts itself with the nearby sibling hypotize_experiments_list, so the boundary between 'experiments' and 'learnings' must be inferred from the tool name alone.

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?

It gives one concrete usage cue ('use it for a weekly review') tied to ended_after, which is genuinely helpful. It offers no guidance on when to choose this over hypotize_experiments_list, nor any prerequisites for the required project_id, so usage is implied rather than stated.

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