Query the SIMBAD astronomical database by object identifier (e.g., M31, NGC 1234, Vega) to retrieve data on stars, galaxies, and other celestial objects.
Query SIMBAD astronomical database by object identifier (e.g. M31, NGC 1234, Vega)
| Name | Required | Description | Default |
|---|---|---|---|
| lang | No | Output language | en |
| object_name | Yes | Astronomical object name or identifier |
Changes observed during successful MCP inspections.
v2.1.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does not say whether the call is read-only, whether it returns a single record or many matches, how ambiguous names are resolved, or whether there are rate limits or auth requirements. For a read query that is likely safe, this is still a large behavioral gap.
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 efficient sentence with the key identifier first and examples last; nothing is wasted. It is arguably under-specified rather than overly long, so brevity is a virtue here, not a flaw.
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?
With 2 parameters, full schema coverage, and no output schema, the description needs to carry the return-shape and disambiguation story — and it does not. It is adequate to attempt a call but leaves the agent guessing about result format and when to prefer a sibling database.
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 the schema already documents both parameters, establishing a baseline of 3. The examples (M31, NGC 1234, Vega) add a little format intuition but nothing about the lang parameter's effect on returned values.
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 (Query) plus resource (SIMBAD astronomical database) and the primary lookup key (object identifier), with concrete examples (M31, NGC 1234, Vega) that make the scope unmistakable. It stops short of distinguishing itself from the near-identical sibling ned_query, which queries a different but comparable database.
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, no exclusions, and no routing among the many name-resolution siblings (ned_query, vizier_query, simbad-adjacent catalogue tools). The use case is only implied by the phrase 'by object identifier'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.