List engine parameters

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds the non-obvious fact that it 'Does not run the engine' plus the return shape ({key, type, enum?, description}). That is meaningful context beyond the safety profile, though it doesn't mention anything about staleness or caching of the catalog.

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 core purpose and the practical 'Does not run the engine' caveat. The middle sentence enumerates all 9 strategy_overrides and 5 runtime_args keys, which is dense but arguably earns its place as the tool's actual payload; it is the one spot that reads as bulky.

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, the description fully compensates by naming both return groups, distinguishing strategy() header fields from run_backtest_full args, and giving the per-entry shape. An agent has everything needed to call and consume this tool correctly.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description instead spends its words on return-value semantics, which is appropriate for a no-arg discovery call.

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 ('Returns the full catalog of engine knobs') and scopes it precisely to the consumers, backtest_pine / backtest_pine_grid. An agent can distinguish this from siblings like check_pine_feature or transpile_pine without opening the schema.

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?

Explicitly says 'Use this to discover what knobs the engine exposes before issuing a backtest,' which names the moment of use and the downstream tool. It lacks an explicit when-not clause (e.g., when the caller already knows the knob names), so it stops short of a 5.

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