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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds useful non-annotation context: 'First-party Valuein content. No data reads. Available on all plans,' which tells the agent there is no external data dependency or plan gating. It stops short of describing result shape, but an output schema exists to carry 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?

Front-loaded with the resource definition, then the call-first directive, then provenance/availability. Mostly earns its space, though the parenthetical playbook enumeration and the mild promotional clause ('materially better results than improvising') are slightly heavier than needed.

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 one-optional-param list tool with rich annotations and an output schema, the description supplies everything an agent needs: what a playbook is, why ordering matters, the call-first rule, the follow-up tool, and plan availability. Return-value details are correctly delegated to the output 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% and the single optional `filter` param is fully documented in the schema with examples ('smart money', 'thesis', 'backtest') and the omit-to-list-all behavior. The description never mentions filtering at all, so it adds no meaning beyond the schema — 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?

States a specific verb and resource ('List Valuein's expert research playbooks') and immediately defines what a playbook is — step-by-step procedures encoding tool sequence, parallel-wave grouping, and output structure. It also enumerates concrete playbook families, so an agent can tell it apart from get_sop (which loads one) 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?

Explicit routing: 'CALL THIS FIRST for any multi-step financial research request, then load the matching playbook with `get_sop`.' Both the trigger condition and the follow-up alternative are named, along with the reason (sequences encode fetch ordering and concurrency). Nothing is left to inference.

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