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

Annotations already declare readOnly and idempotent, so the safety profile is covered. The description adds genuinely non-obvious behavior: the single-position return shape and the crucial caveat that a null `position` with `errors` means an unreadable chain rather than a missing position, which prevents a false negative conclusion.

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 dense sentences, front-loaded with purpose, then preconditions, then the special case. Every clause carries information, though the backticked return-shape detail makes the second sentence heavy for a general reader.

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 no output schema, the description correctly describes the single-position return object and its error semantics. It does not describe the list-mode return shape, but the opening sentence names the key fields (health, leverage, PnL), which is enough for an agent to call it correctly.

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 50% and positionAddress has no schema description, but the description supplies the missing semantics: it must be combined with chainId and not chainIds, and it changes the return shape. It also communicates the 'one of chainId/chainIds is required' constraint that the schema does not enforce.

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?

Opens with a specific verb and resource ('List an owner EOA's Loopr positions') and names the data returned (health, leverage, PnL). It is clearly distinguishable from the build_*/quote_* siblings, which construct transactions rather than read state.

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?

States a hard precondition ('Requires chainId or chainIds') and explains the two modes: owner+chain for a list, positionAddress+chainId for a single position. It omits any statement about when to prefer a sibling tool, but the list-vs-single routing is explicit.

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