Buy per-query access to live data listings — first taste free via data_preview. Listing: nasanewswatch: NASA Mission & Space News (0.01 USDC/query). Returns fund instructions after data_session_open.
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | Yes | UUID of a data session you opened (from data_session_open). |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds that it returns fund instructions after data_session_open, but the opening phrase 'Buy per-query access' could be misread as an actual purchase rather than instructions.
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 compact: two sentences with the main action front-loaded. Some promotional detail ('first taste free', specific listing) is present but not excessive.
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?
It mentions a prerequisite (data_session_open) and the return type ('fund instructions'), but with no output schema the description leaves the exact content and format of those instructions vague.
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?
The schema already fully describes session_id as a UUID from data_session_open, and the description adds no additional parameter-level detail. With 100% 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?
States a clear action ('Buy per-query access') and resource ('live data listings'), with a specific listing and price. It distinguishes itself from data_preview by offering a free preview, though it could more clearly differentiate from data_session_fund.
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?
Provides implied usage context: preview via data_preview, then return fund instructions after data_session_open. However, it does not explicitly say when to use this tool instead of data_session_fund or data_session_attach_escrow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.