fails_to_deliver_searchSearch SEC fails-to-deliver by issuer name or ticker. Returns each security's total fail shares, peak single-day fail balance, and days-with-fails over the rolling 12-month window. CUSIP joins to the SEC securities/13F-holdings layer.
| Name | Required | Description | Default |
|---|---|---|---|
| q | Yes | Issuer name or ticker (>=2 chars) | |
| limit | No | Max results (default 25, max 100) |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this a safe, idempotent, non-destructive read, so the safety profile is covered. The description goes further by disclosing the return shape (total fail shares, peak single-day fail balance, days-with-fails), the rolling 12-month window, and that CUSIP links to the SEC securities/13F-holdings layer — useful context an agent cannot get from structured fields. It omits pagination behavior for the limit parameter.
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 tight sentences: what it searches, what it returns, and the join key. Nothing is wasted and the resource is front-loaded, which is exactly the right structure for a retrieval tool.
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 two-parameter read-only search with full schema coverage and no output schema, the description supplies what is needed: the resource, the lookup key, the returned metrics, and the time window. The remaining omissions (pagination, ordering, and differentiation from fails_to_deliver_top) are minor but keep it short of 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 both parameters are already fully documented (q as name/ticker with >=2 chars, limit with default 25 / max 100). The description restates the q semantics but adds nothing about limit or result ordering. Baseline 3 is appropriate when the schema carries the parameter detail.
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 ('Search SEC fails-to-deliver') plus the accepted lookup keys ('issuer name or ticker'), so the agent knows exactly what it does. However, it never distinguishes itself from the near-identical sibling fails_to_deliver_top, which an agent would reasonably confuse it with.
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?
There is no when-to-use, when-not-to-use, or alternative-tool guidance. The closest thing is a restatement of the query key, which the schema already supplies. With a direct sibling (fails_to_deliver_top) sitting in the same tool list, the absence of routing guidance is a real gap.
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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