fcc-spectrum-mcp-server

Search FCC ULS licenses

fcc_spectrum_search_licenses

Read-onlyIdempotent

Search FCC ULS licenses and spectrum leases by callsign, licensee name, FCC Registration Number (FRN), market code, radio service, status, and licensee state, returning one row per record with its unique system identifier (USI) for fcc_spectrum_get_license. At least one of callsign, licensee, frn, market_code, radio_service, or state is required; status only narrows. Defaults to active records; pass status "any" to include expired, cancelled, and terminated ones. Licensee name matching is word-based (every word must appear as a word prefix), not fuzzy.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`frn`	No	FCC Registration Number, up to 10 digits; spaces and hyphens are removed and it is left-padded with zeros.
`limit`	No	Records per page (1–100).
`state`	No	Licensee mailing state: a two-letter USPS code (incl. DC, PR, VI, GU, AS, MP) or a full state name. This is the licensee's address, not the site location.
`cursor`	No	nextCursor from the previous page of the same search; omit for the first page.
`status`	No	License status: A active, L pending legal, X term pending, E expired, C canceled, T terminated, P parent station canceled, or "any" for every status. Defaults to A.	A
`callsign`	No	Exact callsign or lease ID, e.g. "KNKA123" or "L000012345". Case, spaces, and one trailing portable suffix ("/4") are normalized. ULS reuses callsigns, so several records can match.
`licensee`	No	Licensee name words, with at least one letter or digit; every word must match the start of a word in the name, in any order (e.g. "verizon wireless"). A word joined by - or & ("T-Mobile", "AT&T") matches its pieces side by side.
`market_code`	No	Market code of a geographic-area license, matched exactly, e.g. "PEA016", "CMA020", "D06037", or "NW" (nationwide); results carry it as marketCode. Case, spaces, and hyphens are ignored, and the digits are left-padded with zeros ("pea16" reads as PEA016).
`radio_service`	No	Two-character radio service code, e.g. "CD" (paging) or "BR" (BRS); see fcc_spectrum_list_reference topic "radio_services".

Output Schema

TableJSON Schema

Name	Required	Description
`cap`	No	The page limit applied.
`error`	No	Present when the call failed. Absent on success.
`shown`	No	Records on this page.
`notice`	No	Why nothing matched, what redaction excluded, or how to page further.
`dataAsOf`	No	Creation time of the newest applied ULS file (ISO 8601).
`licenses`	No	Matching records, ranked by name-match relevance when licensee is given and in callsign order otherwise.
`truncated`	No	True when more records follow this page.
`nextCursor`	No	Pass as cursor with the same filters for the next page; absent on the last page.
`totalCount`	No	Records matching the filters, across every page.
`appliedFilters`	No	Filters as the server applied them, normalized values and defaults included.

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 2, 2026

TDQS

A4.4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark it read-only and idempotent, so the safety profile is covered. The description still adds meaningful behavior beyond that: the default-to-active filtering and the word-prefix (non-fuzzy) matching semantics of licensee names, which an agent could otherwise get wrong.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads the core purpose, then adds constraint, default-status, and matching-semantics sentences. Four sentences, all carrying distinct information with no repetition, though it is dense enough that a slight trim would improve it.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need not be explained. The description fully covers the invocation constraints, default filtering, status override, and matching caveats for a nine-parameter search tool, leaving nothing an agent needs missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% so the schema documents each parameter's format, keeping this near the baseline of 3. The description goes beyond it by stating the cross-parameter constraint (at least one of callsign/licensee/frn/market_code/radio_service/state required), which is not expressed via JSON Schema required fields, plus the status-narrowing rule.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Search) and resource (FCC ULS licenses and spectrum leases), enumerates the filterable fields, and precisely describes the return shape (one row per record with USI). It also names the follow-up sibling fcc_spectrum_get_license, so an agent can distinguish it from find_transmitters and search_frequencies.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete conditions: at least one of the six search fields is required, status only narrows, and status "any" is needed to include expired/cancelled/terminated records. It explains the follow-up tool by name, but does not explicitly contrast against the other search siblings, keeping it short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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