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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds behavior the annotations cannot: results are newest-first, exactly one summary row per book, and ungraded date ranges yield an empty list rather than an error — useful for an agent interpreting results. It stops short of describing the default 60-row cap or any pagination semantics.

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?

Three sentences, front-loaded with the output shape, then the domain definition, then the routing advice. No sentence repeats the name or title, and the terminal empty-list note is a single useful clause.

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 an output schema present, return values need not be spelled out, yet the description still summarizes the row contents and ordering, and covers the empty-result edge case plus next-step tools. The only minor gap is that it doesn't flag the default limit of 60 or what happens when more books exist than the cap allows, leaving that entirely to the schema.

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%, with limit, from_date and to_date each documented inline including format (YYYY-MM-DD) and bounds. The description mentions only 'trading_date' and 'date' generically and adds no syntax or filtering nuance beyond the schema, so the baseline 3 applies.

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 opens with a specific verb and resource ('List graded books') and then defines the domain term explicitly ('A book (or batch) is one trading day's full S&P 500 slate'). It also enumerates the summary row fields (date, returns, alpha against SPY and RSP, verdict), making it distinguishable from get_resolved_batch, which handles a single book.

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 an explicit workflow: use this tool to find a trading_date, then call get_resolved_batch for every forecast or verify_batch for the proof. That names the alternatives and the condition that selects each, so an agent knows exactly where this tool sits in the chain.

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