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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false, so the safety profile is covered. The description adds the return shape, which is useful, but says nothing about auth needs, compute cost, or failure modes for an inverse-contract edge case it hints at. Adequate but not rich.

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 sentences, front-loaded with the capability, then differentiation, then trigger phrases and returns. The middle sentence is slightly wordy ('output for the case where... is also wanted') but every sentence carries information.

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?

Read-only, no output schema, yet the description enumerates the return fields (averageEntry, breakeven, per-level summary), which compensates for the missing schema. The main residual gap is the undocumented required 'side' parameter and edge-case behavior.

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 60% and the description adds no parameter meaning at all. It never mentions the required 'side' (long/short) parameter, nor contractType or the fee rates, and 'multiple fill prices and sizes' merely restates 'entries'. One point of clear guidance was available here (e.g. when side flips breakeven) and is absent.

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+resource ('DCA entry planner') and enumerates the exact outputs (weighted average entry price, breakeven, per-level contribution). It explicitly contrasts itself with the sibling primitive.average_entry, so an agent can distinguish the two 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 selection rule ('use when breakeven or the per-level breakdown is also wanted, not just the bare average') and names the alternative tool plus the condition that selects it. Also supplies concrete trigger utterances for when to invoke.

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