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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=true, so the mutation profile is known; the description adds the plan entitlement requirement and the feed-health dependency, both real behavioral gates. It omits the refusal-on-stale-version behavior, but the schema's parameter descriptions already document that.

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 short sentences with no filler; the core action comes first and the prerequisites follow. Nothing is repeated from the schema or annotations.

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 mutating tool with an output schema present, return values need not be described, and the prerequisites plus parameter guidance are covered between description and schema. Only the post-start lifecycle (whether a run id or job is returned, how to stop it) is left implicit, which the output schema likely handles.

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 strategy_id, draft_version, account_version, and idempotency_key are all fully explained in the schema itself. The description adds no syntax or semantics beyond pointing at get_paper_status, which is baseline behavior when the schema does the heavy lifting.

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: 'Start a paper run of one of the caller's strategies on the live feed (simulated money)'. The parenthetical clarifies that this is simulated capital, separating it from real trading, though it never names the neighboring tools (validate_paper_strategy, simulate_strategy, save_paper_strategy) it should be distinguished from.

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?

Gives concrete preconditions — a Pro plan and a healthy feed, with get_paper_status named as the check to perform first. It does not, however, state when to prefer this over validate_paper_strategy or simulate_strategy, nor what to do if the preconditions fail.

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