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

With no annotations, the description carries the burden and does well: it discloses units (USDG raw, 1e6), sign convention (signed from the account's side), which position states are included, and the cost/realized breakdown, plus the presence of a `summary` field. What it omits is whether the call is read-only/cheap, whether it needs auth, and how large the response can get for accounts with many positions.

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?

One dense sentence with the resource front-loaded and then the return contents, units and sign convention, all of which earn their place. Slightly run-on, but no 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?

For a read tool with no output schema, no annotations and one parameter, the description explains the return payload and its units well enough to call and interpret it. The missing pieces are the account identifier format and any hint about cost/size of the response.

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 0% for the single `account` parameter, so the description should define the identifier format (address, account id, subaccount?) and does not. The parameter's meaning is at least obvious from context, so it is not a total gap, but it fails to compensate for the empty schema.

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 resource (PnL of an account) and enumerates exactly what is returned: every position in any state, mark, unrealized/realized PnL, fees, total, plus a summary line. It does not distinguish itself from the closest sibling, get_positions, leaving the agent to infer the difference.

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?

No statement of when to use this versus get_positions (which presumably returns the same positions without PnL) or get_history. Usage is only implied by the resource name; there are no exclusions or alternative routing.

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