Retrieve stored market-data rows for a channel and multiple symbols within a nanosecond time range; optionally limit returned rows.
Stored rows for one channel and symbols within a nanosecond time range.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| end_ns | Yes | ||
| channel | Yes | ||
| symbols | Yes | ||
| start_ns | Yes | ||
| asset_class | No | Which market answers. Inferred from the symbol's source when omitted. |
Changes observed during successful MCP inspections.
v0.3.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden, yet it says nothing about read-only semantics, ordering, default row limits, or the `row_limit` ceiling that the schema mentions. 'Stored rows' weakly implies a read, but no operational traits are disclosed.
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?
It is short, but that brevity is under-specification rather than efficiency: a single fragment with no lead verb and no structured front-loading of the constraints the schema elsewhere argues for. Nothing an agent needs to act is established before the sentence ends.
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 6-parameter tool with no annotations, no output schema, and 17% schema coverage, the description is far too thin — it should explain the nanosecond-unit trap, the multi-symbol merge, and the limit ceiling, all of which the schema privately documents but the description never surfaces.
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?
Only 1 of 6 parameters (asset_class) has any schema description, so coverage is 17% and the description must compensate — but it adds nothing about `channel`, `symbols`, `start_ns`/`end_ns`, or `limit` semantics. The rationale text lives in the schema's `$defs`, not in the tool description, so an agent skimming the description learns nothing about parameter meaning.
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 sentence identifies the resource (stored rows), the key dimensions (one channel, multiple symbols, nanosecond time range) and the data it touches, which is more than the bare name provides. But it is a fragment with no verb and doesn't distinguish this scan from the sibling `query` or `catalog` tools, so an agent can't tell why it should pick this one.
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 guidance on when to use this tool rather than `query`, `catalog`, `catalog-symbols`, or `catalog-dates`, all of which appear in the sibling list and touch similar data. No preconditions, exclusions, or alternatives are mentioned anywhere.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.