List future expiration dates for a ticker's listed options.
Excludes past expirations. Use the result as input to get_options_chain.
Also use it FIRST when the user asks for greeks, IV or delta on a
ticker's options: the chain it leads to is the data we can present.
Args:
ticker: Underlying ticker (e.g. 'AAPL').
| Name | Required | Description | Default |
|---|---|---|---|
| ticker | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -{
- "properties": {
- "result": {
- "title": "Result",
- "type": "string"
- }
- },
- "required": [
- "result"
- ],
- "title": "get_options_expirationsOutput",
- "type": "object"
-}New value: +nullDoes the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover readOnly, idempotent, openWorld, and non-destructive behavior. The description adds useful filtering context ('Excludes past expirations') and clarifies its role as a prerequisite for chain data, which goes beyond the structured annotations.
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 purpose, then provides usage guidance and a brief args block. The wording is slightly roundabout in the greeks/IV sentence, but overall it is efficient and well-structured.
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, single-parameter read tool with full safety annotations, the description covers purpose, usage, and parameter meaning. Missing details like date format or sorting order are minor and not critical for correct invocation.
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 0%, so the description must carry the full burden. It identifies the parameter as 'Underlying ticker' and provides an example ('AAPL'), which is sufficient for a single, straightforward ticker parameter.
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: 'List future expiration dates for a ticker's listed options.' This clearly distinguishes it from get_options_chain and other option-related siblings by focusing on expirations rather than the chain itself.
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?
Explicitly routes the agent: 'Use the result as input to get_options_chain' and 'Use it FIRST when the user asks for greeks, IV or delta.' The condition for use and the downstream relationship are both stated, leaving little inference needed.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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