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

The annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description does not need to restate that. It adds real value beyond them by disclosing the error behavior for ungraded dates and out-of-book tickers, plus what evidence is returned. It stops short of describing response shape in detail, but an output schema exists for 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 tight sentences, front-loaded with the purpose and followed by the usage routing and error rule. Dense but every clause earns its place; the first sentence is long and comma-heavy, which slightly reduces scannability.

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 two-parameter read tool with full schema coverage and an output schema, the description supplies what structured fields cannot: when to prefer the sibling, what evidence comes back, and what counts as an error. Little is missing for correct invocation.

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 coverage is 100%, and the schema already explains the ticker's case-insensitivity and the YYYY-MM-DD date format with a pointer to list_resolved_batches. The description adds only the failure semantics for these two inputs, so the baseline of 3 is appropriate.

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 states a specific verb and resource ('Get the stored evidence behind one stock's forecast in a graded book') and immediately enumerates what that evidence includes: rank, side, regime, lookback returns, news and notes. It also explicitly distinguishes itself from the sibling get_stock_resolved_history, so an agent can choose between them without opening either 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?

It gives explicit when-to-use guidance ('Use this to see the context a stock was ranked in') and names the alternative and its condition ('get_stock_resolved_history to find which books hold it'). It also states the failure conditions — an ungraded date or a ticker absent from the book is an error — which is exactly the guidance needed to avoid a bad call.

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