fails_to_deliverRetrieve SEC fails-to-deliver quantities and prices by settlement date for a ticker, or identify the largest fails by value in the latest settlement.
SEC fails-to-deliver quantity and price by settlement date for a symbol, or the latest settlement's largest fails by value.
| Name | Required | Description | Default |
|---|---|---|---|
| symbol | No | US ticker symbol, e.g. GME. Class shares as on the SEC list, e.g. BRK-B. |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It implies a read-only data lookup but never states read-only behavior, pagination, rate limits, coverage window, or freshness of the settlement data. It does disclose the dual output shape, which is useful, but that is mostly return-content description rather than behavioral traits.
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?
A single dense sentence that front-loads the resource and covers both output modes with no filler. It is slightly compressed ('fails-to-deliver quantity and price') but nothing is wasted.
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?
No output schema exists, so the description must convey return content; it does identify the two return shapes (time series by settlement date, or largest fails by value). However, it omits when each mode applies and freshness/coverage, leaving an agent unable to call it confidently in all cases.
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% and the single symbol parameter is fully documented in the schema with format examples (GME, BRK-B). The description only echoes 'for a symbol' and adds no syntax or semantics beyond the schema, so the baseline 3 applies.
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 names a specific resource (SEC fails-to-deliver quantity and price) and the keying dimension (settlement date, or the latest settlement's largest fails by value). An agent can tell this is a data-retrieval tool distinct from siblings like short_interest or short_volume, though it doesn't explicitly distinguish itself from those near-neighbors.
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?
No when-to-use guidance is given, and crucially the two output modes ('by settlement date for a symbol' vs 'the latest settlement's largest fails by value') are not tied to a selection condition, so the agent cannot tell what triggers each mode. No alternatives are named among the many sibling market-data tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.