get_collections
Search NASA CMR collections and return up to 10 lightweight normalized results.
Key return fields in each item:
concept_id: CMR collection concept ID
native_id: native ID of the collection record
revision_id: revision ID of the collection metadata
provider_id: provider ID of the collection
short_name: collection short name
entry_title: collection title
time_start / time_end: temporal coverage bounds
processing_level_id: processing level (e.g., L3, L4)
doi: digital object identifier
collection_data_type: data type (e.g., SCIENCE_QUALITY, NEAR_REAL_TIME)
temporal_resolution / spatial_resolution: extracted resolution strings
related_urls: links to landing pages, documentation, and tools
Unfiltered searches are supported when you need broad exploration.
IMPORTANT — relevance and coverage: A keyword-only search returns all collections whose metadata mentions those terms, regardless of whether they actually hold data for the user's region or time period. Collection declared extents are often global or multi-decadal, so a collection appearing in results does not mean it has granules for a specific area or date. When the user's question involves a time period or geographic region, include temporal_start_date/temporal_end_date and/or spatial_wkt_geometry to restrict results to collections that overlap that window. Follow up with get_granules (with the same filters) to confirm actual data availability.
IMPORTANT — keyword AND logic: CMR treats each space-separated keyword as an independent term and requires ALL of them to appear somewhere in a collection's metadata (title, summary, science keywords, instruments, platforms, etc.). Words do not need to appear in the same field or adjacent to each other. Because every term must match, adding more words makes the search STRICTER, not broader — the opposite of typical web search engines. Prefer 2–4 precise scientific terms. If a search returns 0 results, try removing the least essential word before broadening other filters. Phrase search (exact word sequence) is available by wrapping the value in escaped double quotes, but you cannot mix a phrase with additional standalone keywords.
Key parameters:
keyword: free-text keyword search over collection metadata (AND logic; see above)
concept_id: exact collection concept ID
short_name: collection short name
provider: data provider short name
temporal_start_date / temporal_end_date: restrict to collections whose declared range overlaps this window; set when the user specifies a time period
spatial_wkt_geometry: restrict to collections whose declared extent intersects this area; set when the user specifies a geographic region
Iteration & Refinement:
Results are strictly capped at 10 items to optimize context window usage.
If total_hits exceeds 10 and you lack the necessary results, do not attempt to page. Refine your search by adding tighter spatial, temporal, or keyword constraints.
Tips:
Use scientific terms (variables, instruments, platforms) for better keyword relevance
Keep keyword queries to 2–4 precise terms; more words = stricter filter
If 0 results, drop the least essential keyword and retry before broadening other filters
Combine keyword + temporal + spatial filters for highest precision
Use short_name when you already know the target product
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Maximum number of results to return (default 10, max 50). Keep this small to avoid context window bloat. When using limit > 10, always specify the fields parameter. | |
| cursor | No | Pagination token for the next page of results. Pass the exact next_cursor string returned by the previous tool call. Cursors are query-scoped: they lock in the original search parameters and cannot be reused across different tools or different queries. If you need to change any search parameter, start a new search without a cursor. | |
| fields | No | ||
| keyword | No | Free-text keyword search. Case insensitive. IMPORTANT — CMR uses AND logic: each space-separated word is matched independently and ALL words must appear somewhere in a collection's indexed fields (title, summary, short name, GCMD science keywords, platform and instrument names, project names, processing level, archive centers, additional attributes, etc.). Words do NOT need to appear in the same field or as a contiguous phrase. Because every word must match, adding more words makes the search STRICTER, not broader — the opposite of typical web search engines. Prefer 2–4 precise terms over long queries. Example: 'soil moisture' (2 terms, broad) vs 'soil moisture SMAP L3' (4 terms, narrow). Phrase search: wrap the entire value in escaped double quotes to require an exact phrase (e.g., '\"sea surface temperature\"'). Only a single phrase is supported; you cannot mix a phrase with additional standalone words. Wildcards supported: * (zero or more chars), ? (any single char). Use scientific terms: geophysical variable names ('sea surface temperature', 'soil moisture'), instrument names (MODIS, ASCAT, VIIRS, AIRS, Landsat, etc.), or platform names (Terra, Aqua, SMAP, Sentinel-1, etc.). For known product short names use the short_name parameter instead. | |
| platform | No | ||
| provider | No | Data provider short name (e.g., PODAAC, NSIDC_ECS, GES_DISC, ORNL_DAAC, LAADS, GHRC_DAAC, ASDC). Restricts results to collections from that provider. WARNING: NASA DAACs are actively migrating assets to the cloud under new provider IDs (e.g., LPDAAC_ECS → LPCLOUD, PODAAC → POCLOUD). If you know the exact short_name of a product, do NOT include the provider parameter — a stale provider ID will silently return 0 results. Use provider only when the user explicitly filters by archive center. | |
| concept_id | No | Exact CMR concept ID (format: C<number>-<PROVIDER>, e.g., C2036882064-POCLOUD). Use for direct lookup of a known collection. | |
| instrument | No | ||
| short_name | No | Collection short name (e.g., MOD11A1, SPL3SMP, MUR-JPL-L4-GLOB-v4.1). Exact match by default; wildcards * and ? are supported. | |
| has_granules | No | When True, filters to collections that have actual granule data. Prevents returning metadata-only shells. | |
| temporal_end_date | No | End of temporal filter in ISO 8601 format (e.g., 2020-12-31T23:59:59Z). Restricts results to collections whose declared temporal range overlaps this window. Set this whenever the user specifies a time period — omitting it returns collections regardless of when their data was collected. | |
| processing_level_id | No | ||
| temporal_start_date | No | Start of temporal filter in ISO 8601 format (e.g., 2020-01-01T00:00:00Z). Restricts results to collections whose declared temporal range overlaps this window. Set this whenever the user specifies a time period — omitting it returns collections regardless of when their data was collected. | |
| spatial_wkt_geometry | No | Spatial filter as WKT geometry. Supported types: POLYGON((lon lat, ...)), POINT(lon lat), or LINESTRING(lon lat, ...).Restricts results to collections whose declared extent intersects this area. CMR returns any collection that touches this shape, so precise geometries are preferred to prevent false positives. Set this whenever the user specifies a geographic region — omitting it returns collections with global or unspecified coverage. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| status | Yes | Status of the tool execution | |
| total_hits | No | Total number of matching items | |
| collections | No | Normalized collection results mapped from UMM-C | |
| next_cursor | No | Pagination token for the next page of results | |
| error_message | No | Error details when status is error |