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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), so the bar is lowered; the description still adds real value: data is private to the calling key, no public Arena user can see it, it is paper trading in virtual mUSD, and fills follow paper_execution_v1 with a disclosed execution cost. It does not mention rate limits or pagination beyond the 1,000-row cap.

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?

Four compact sentences, front-loaded with the core action and row limit, then constraints and execution model. Slightly dense with execution-model detail that could be trimmed, but nothing is wasted.

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 explained, and the description adequately covers privacy, scope, row limit, and execution semantics. The main gap is the absence of differentiation from get_agent_ledger, which is relevant given the overlapping resource.

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% across all 8 parameters, including the nested agentTrace object, so the schema does the heavy lifting and baseline 3 applies. The description adds only that runId and decisionId are useful for reproducible evaluation, which is marginal beyond the schema text.

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 (Export) and resource (private agent ledger rows) with scope (up to 1,000 rows, calling API key, JSON). However, it never distinguishes itself from the closely named sibling get_agent_ledger or the adjacent export_run_evidence, leaving the agent to infer which one to use.

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 suggests a usage pattern — filtering by runId or decisionId for reproducible evaluation — which implies a use case. But it offers no explicit when-to-use vs. get_agent_ledger or export_run_evidence, and no guidance on when filters should be omitted.

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