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

Annotations already declare readOnlyHint=true, establishing this as a safe read operation. The description adds context about the interpretation of the output (dealer hedging changes over time) but does not disclose other behavioral traits like output structure, data availability, or any limitations. It neither contradicts annotations nor provides significant extra transparency beyond the annotation.

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?

The description is two short sentences, front-loaded with the tool name and core purpose. The first sentence states what is retrieved, and the second adds essential interpretive context without redundancy or filler. Every word contributes value.

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 relatively simple read-only tool with three fully documented parameters and no output schema, the description provides the core concept but is missing details about the return format (e.g., list of strikes with values) and how it differs from related tools like get_historical_chex or get_exposure_summary. It is sufficient for basic understanding but not fully complete.

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 all parameters (apiKey, symbol, expiration) already have documented meanings. The description adds 'by strike' as an output dimension but does not elaborate on how expiration filtering works or how parameters map to the result. With full schema coverage, the baseline of 3 is appropriate.

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?

The description states a specific verb ('Get') and resource ('charm exposure (CHEX)') with an explicit scope ('by strike'), and the second sentence explains what the metric reveals ('how dealer delta hedging changes as time passes'). This clearly distinguishes it from sibling tools like get_dex or get_gex, which focus on immediate delta or gamma.

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?

The description implies the tool is for time-decay-driven flow analysis ('reveals time-decay-driven flows'), but it does not explicitly state when to use it versus alternatives such as get_dex, get_gex, or get_exposure_summary. There is no mention of exclusions or when not to use it, leaving usage to be inferred.

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