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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered; the description adds that output is raw numbers only with no verdict, which is real behavioral context. It doesn't discuss assumptions (e.g., interval normalization or fee handling), which keeps it below a 5.

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?

Three tight sentences, front-loaded with the calculation, followed by the differentiation rule and the return fields. Every clause carries information the agent needs; nothing is redundant with the name/title.

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 usefully enumerates return fields, and the calculation inputs are fully documented in the schema. The gap is sibling landscape: several near-neighbors (run_funding_breakeven, run_funding_cost, run_compound_funding, run_cross_venue_arbitrage) go undifferentiated, which the agent may need when selecting among them.

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 100% and every parameter carries its own units/format notes (e.g., per-interval percentages, 0.1 for 0.1%), so the schema does the heavy lifting. The description only hints at transfer fees via an example question and adds no syntax or defaulting details beyond the schema – baseline 3.

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 ('Calculate funding rate arbitrage profit') and enumerates the three outputs (annualized yield, net profit, breakeven days) for a long/short basis trade across two exchanges. It explicitly distinguishes itself from sibling workflow.run_carry_trade, so an agent can choose 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?

Gives an explicit routing rule: for the same math plus a verdict, use run_carry_trade instead. It also anchors usage to concrete user phrasings ('is this funding arb worth it?', 'how many days to break even on transfer fees?'), leaving little to inference.

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