Buy per-query access to live data listings — first taste free via data_preview. Listing: nasaiotd: NASA Image of the Day (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?
The description says 'Returns fund instructions' which correctly indicates a non-mutating read-only behavior, aligning with the readOnlyHint and destructiveHint annotations. The word 'Buy' could imply a purchase action, but the elaboration that it returns instructions avoids a direct contradiction.
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 a single compact sentence with a dash for a side note, efficiently conveying the core purpose, the listing, and the prerequisite. No unnecessary fluff.
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 one-parameter tool, it adequately mentions the prerequisite session and the free preview alternative, but it does not explicitly reference related funding actions (e.g., data_session_fund) or explain how the returned instructions are to be used, which would make the context more 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?
The only parameter, session_id, is fully documented in the schema: it is a UUID of a data session opened via data_session_open. The description covers 100% of the schema and provides clear context on how to obtain the value.
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 clearly states the tool returns fund instructions for per-query access to a specific live data listing (NASA Image of the Day). The phrase 'first taste free via data_preview' provides a contrast that helps anchor its purpose, though 'Buy' is slightly ambiguous as it actually provides instructions rather than executing a purchase.
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?
It mentions the prerequisite data_session_open and the alternative data_preview for a free taste, but it does not explicitly distinguish itself from sibling tools like data_session_fund or data_session_attach_escrow, leaving some ambiguity about when to use this vs. those tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Several tools occupy overlapping roles: data_session_fund, data_session_funding_package, and data_session_attach_escrow all handle payment for the same data listing, while a2awire_guide and get_recommended_action both provide navigation guidance. Descriptions clarify some sequencing, but an agent could easily misselect among the payment/session tools. The boundary between onboarding tools (register, onboard_start, get_recommended_action) is also fuzzy.
Most tools use snake_case, but the verb/object order is inconsistent: data_session_* tools are object-first (data_session_open, data_session_query), while most others are verb-first (check_earnings, discover_agents, verify_contract). There are also one-off forms like a2awire_guide, data_preview, register, and hire_and_execute that break the pattern. The naming is readable but not predictable.
16 tools is excessive for a server presented as 'NASA Image of the Day — space & astronomy photos,' since most tools are unrelated marketplace, escrow, and onboarding machinery. Only data_preview and the data_session_* tools actually serve the NASA image domain. The count may fit a broader A2AWire platform, but it is disproportionate to the server's stated purpose.
The actual NASA image surface is thin: data_session_query is the only retrieval tool and it requires a multi-step paid session setup. More importantly, find_paid_work explicitly tells agents to call start_job, but no start_job tool exists, creating a dead end in the advertised workflow. The set also lacks direct tools for browsing images or managing sessions after opening them.