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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it discloses the default nearest expiration, that it returns a call and put, and that the output is ids. It does not cover error handling or rate limits, but with annotations present this is adequate.

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?

Front-loads the core definition in the first sentence and follows with the practical downstream usage in the second. Every clause earns its place; no filler or repetition.

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 simple two-parameter lookup with no output schema, the description is complete enough: it defines ATM, notes the default expiration, and says what the output contains (call/put and ids). It could optionally mention when to prefer a different tool like options_chain, but the essential information for correct invocation is present.

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%, so both the symbol and expiration parameters are already documented in the schema, including the default-to-nearest-expiration behavior. The description largely duplicates this with 'front/nearest expiration by default' and adds no syntax or format detail beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (ATM option contracts for a symbol) and defines it precisely: the call and put whose strikes are closest to the current stock price, within one expiration. Distinguishes itself from a full options chain by scoping to ATM legs and identifies the downstream tools that consume the returned ids.

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?

Clearly indicates the context of use by naming the downstream tools (simulate_position, simulate_pnl, paper_trade) that should receive the ids. It also documents the default expiration behavior. It does not explicitly compare against alternatives like options_chain or pick_position, but the context is clear without being misleading.

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