optimization.compare_results

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

With no annotations, the description carries the full burden and does add genuine behavioral context: it discloses the comparable=false condition and that no single improvement percentage is emitted, which prevents misreading the output. It still omits that this is a read-only operation and what happens for invalid inputs (fewer than 2 runs, unknown IDs).

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?

Front-loaded with the action and scope, followed by the one behavioral caveat that matters. Every sentence earns its place; the only minor cost is the inline code formatting of comparable=false.

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?

An output schema exists, so return structure needn't be explained, and the description covers the one non-obvious output semantic (comparable=false). For a 2-parameter read tool this is sufficient for correct invocation, with compare_fields the sole residual gap.

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?

run_ids gains real meaning from the '2–10 runs' constraint, which the schema itself does not encode (no minItems/maxItems). However compare_fields — the only other parameter, defaulting to null — is never explained; the list of mismatch axes (objective, variables, constraints, evaluator versions, parameters) hints at it but doesn't say whether those strings are valid values.

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 and resource (compare runs) with an explicit cardinality bound (2–10) and the outcome it produces (condition mismatch report). It is clearly distinguishable from siblings like get_result or list_runs, though it never names them.

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 2–10 run bound implies a batch comparison context, and the mismatch clause hints at when the result is not a simple delta. But there is no explicit guidance on when to prefer this over get_result or how to prepare inputs (same problem/objective baseline).

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