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

Annotations already declare read-only and idempotent hints; the description adds the event-counting rule, live Chainlink price join, and mode filter semantics. This enriches understanding beyond what annotations alone convey.

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?

The description is compact and front-loaded with the core concept, followed by parameter details. Every sentence contributes meaningful information without redundancy or filler.

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?

The derivation logic and P&L inclusion are clearly specified, but with no output schema, the return structure is not described (e.g., whether positions are aggregated, pagination, field list). It is adequate for basic use but not fully complete for complex expectations.

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 0%, but the description compensates by enumerating valid values for both parameters ('agent: gap-trader | narrative-trader', 'mode: '' | paper | live | onchain') and explaining mode's meaning. It does not mention defaults, though the schema provides those.

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 clearly identifies the tool as a 'server-side derived open position book' with precise derivation logic, making the resource unambiguous. It distinguishes from 'raw agent events' but does not explicitly compare to sibling tools or use an action verb like 'get' or 'list'.

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 states 'Replaces rebuilding the book from raw agent events,' which implies when to use this tool versus an alternative. The agent and mode filters are listed with allowed values, providing clear context. It does not explicitly state exclusions, but the open-position definition implicitly sets boundaries.

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