MCP server for the CrawlGraph backlink-intelligence API. Gives any MCP client - Claude Desktop, Claude Code, Cursor, Cline, Zed, Windsurf - backlink lookups and competitor gap analysis built on the public Common Crawl webgraph (4.4B edges, 120M domains).
Scored across 5 tools
backlinks (single snapshot) vs backlink_changes (comparison across releases) are clearly separated, and releases is orthogonal. The only real overlap is gap_analysis vs gap_outreach_targets, since the latter explicitly 'runs a gap analysis' then ranks it, so it acts as a superset that could confuse selection.
Consistent snake_case throughout, and related tools share prefixes (backlinks/backlink_changes, gap_analysis/gap_outreach_targets). Minor deviations: backlinks vs backlink_changes switch singular/plural, and backlinks/releases are bare nouns while others are noun_noun compounds.
Five tools is a tight, well-scoped surface for a Crawlgraph/backlink data service, with each tool earning its place (releases, backlinks, comparison, gap analysis, ranked outreach). No redundancy or padding.
Covers the core lifecycle: discover releases, look up backlinks, compare across snapshots, and run gap/outreach analyses. Minor gap: no standalone domain-authority or bulk/batch lookup aside from what backlinks returns, but agents can work around this.
Compare referring-domain observations between two Common Crawl releases. When from_release and to_release are omitted, the API chooses the newest queryable release pair. Costs one backlinks call against the monthly quota. A removed domain means it was not observed in the newer Common Crawl snapshot, not that deletion from the live web has been proven. comparison_available: false is a valid successful response when two queryable snapshots do not exist.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Target domain, e.g. 'example.com'. | |
| to_release | No | Newer Common Crawl release id. | |
| from_release | No | Older Common Crawl release id. |
| Name | Required | Description |
|---|---|---|
| cap | Yes | |
| added | Yes | |
| counts | Yes | |
| domain | Yes | |
| message | No | |
| removed | Yes | |
| truncated | Yes | |
| to_release | Yes | |
| from_release | Yes | |
| authority_moved | Yes | |
| snapshot_caveat | Yes | |
| comparison_available | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, open-world, non-destructive. The description adds attributes annotations cannot express: it consumes one backlinks call from the monthly quota, 'removed' means only not-observed in the newer snapshot (not proven live-web deletion), and comparison_available:false is a legitimate success state. These are exactly the behavioral caveats an agent needs.
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?
Four tight sentences, each carrying distinct information (purpose, defaults, cost, interpretation caveat, valid edge-case response). The core action is front-loaded and nothing is redundant.
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?
An output schema exists, so return-value documentation is not required, yet the description still covers the one return state an agent could misread as failure (comparison_available:false). With quota cost, default behavior, and result interpretation all addressed, nothing material is missing.
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 baseline is 3, but the description adds the non-obvious default behavior: both release parameters are optional and the API selects the newest queryable pair when omitted. That is semantic value beyond the schema's terse 'Newer/Older Common Crawl release id' strings.
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 and resource ('Compare referring-domain observations between two Common Crawl releases'), which clearly separates it from the sibling 'backlinks' (single snapshot) and 'releases' (release listing). An agent can tell what it does without opening the schema.
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?
Explains the default path when from_release/to_release are omitted (API picks the newest queryable pair) and notes the quota cost, which frames when the call is worthwhile. It does not explicitly route an agent to alternatives such as 'backlinks' for single-release data, so routing guidance is implied rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Look up referring domains (backlinks) for a single target domain from the Common Crawl webgraph. Returns each linking domain with host count and CrawlGraph authority score, plus the target's own authority/rank. Costs one backlinks call against the monthly quota (1,000/mo on lifetime).
| Name | Required | Description | Default |
|---|---|---|---|
| sort | No | 'authority' (default) or 'hosts'. | |
| limit | No | Max rows (1..10000, default 1000). | |
| domain | Yes | Target domain, e.g. 'stripe.com'. | |
| release_id | No | Common Crawl release id (defaults to latest; see the releases tool). |
| Name | Required | Description |
|---|---|---|
| domain | Yes | |
| cg_rank | Yes | |
| results | Yes | |
| returned | Yes | |
| release_id | Yes | |
| cg_authority | Yes | |
| release_label | Yes | |
| total_linking_domains | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive. The description adds the critical quota usage detail (1,000/mo) and data source (Common Crawl webgraph), providing extra behavioral context beyond annotations.
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?
Extremely concise: two sentences. First sentence front-loads purpose and output, second adds quota info. No filler.
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 good annotations, full schema, and output schema, the description covers purpose, source, output summary, and quota. Missing a note on default sort or pagination, but otherwise very 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?
Schema coverage is 100% so baseline is 3. The description does not add any parameter-specific meaning beyond what the schema already provides; it mainly describes output behavior.
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 looks up referring domains for a single target domain from Common Crawl, specifying the output (linking domain, host count, authority score, target authority/rank). This distinguishes it from siblings like gap_analysis or releases.
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?
The description mentions quota cost but does not explicitly state when to use this versus alternatives like gap_analysis or releases. It implies use for backlink data but lacks exclusion criteria or comparative guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Run a competitor backlink gap analysis: find domains that link to one or more of your competitors but NOT to you. Submits an async job and polls until done (usually 5-30s). Returns every gap with found_on listing which competitors each domain links to. Costs one gap job against the monthly quota (50/mo on lifetime).
| Name | Required | Description | Default |
|---|---|---|---|
| my_domain | Yes | Your domain. | |
| competitor_domains | Yes | 1 to 5 competitor domains. |
| Name | Required | Description |
|---|---|---|
| gaps | Yes | |
| my_domain | Yes | |
| total_gaps | Yes | |
| competitor_domains | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds significant behavioral context beyond annotations: async job with polling (5-30s), return format with 'found_on' listing, and quota limits (50/month). Annotations already indicate readOnly, openWorld, idempotent, and non-destructive, and the description aligns without 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 concise with three sentences. The first sentence front-loads the purpose, followed by operational details and return info. No unnecessary words.
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?
Given the presence of an output schema (context signals indicate true), the description adequately covers return format and execution behavior. Quota and async details are included. Slight improvement could mention output schema existence or pagination, but overall 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?
Schema description coverage is 100%, with both parameters (my_domain, competitor_domains) well-described in the schema. The description does not add extra parameter-specific semantics, so baseline score of 3 applies.
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 performs a competitor backlink gap analysis, specifically finding domains linking to competitors but not to the user's domain. It distinguishes itself from siblings like 'backlinks' and 'gap_outreach_targets' by specifying the unique gap analysis functionality.
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?
The description explains when to use the tool (to find linking domains) and provides context on async job execution and quota costs. However, it does not explicitly state when not to use it or contrast with alternatives, though the sibling list implies distinct use cases.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
The warm-outreach play. Runs a gap analysis, then ranks results: PRIORITY = domains linking to ALL your competitors but not you (publishers who cover your whole space and have never heard of you), SECONDARY = domains linking to 2+ competitors. Platform/CDN noise is filtered, top N priority targets are scored by authority. Use 2-3 competitors. Costs one gap job + one backlinks call per enriched target.
| Name | Required | Description | Default |
|---|---|---|---|
| my_domain | Yes | Your domain. | |
| enrich_top | No | Authority-score the top N priority targets. Default 10; each costs one backlinks call. 0 disables. | |
| include_platforms | No | Keep platform/CDN/social domains in the list. Default false. | |
| competitor_domains | Yes | 2 to 5 competitor domains (2-3 recommended). |
| Name | Required | Description |
|---|---|---|
| my_domain | Yes | |
| total_gaps | Yes | |
| priority_targets | Yes | |
| secondary_targets | Yes | |
| authority_enriched | Yes | |
| competitor_domains | Yes | |
| platforms_filtered | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Discloses costs ('one gap job + one backlinks call per enriched target'), noise filtering, and ranking behavior. Adds value beyond annotations (readOnlyHint, etc.) by detailing operational impact.
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?
Concise 5 sentences, front-loaded with key purpose, each sentence adds unique value. No redundancy or filler.
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?
Covers purpose, ranking logic, costs, filtering, and parameter specifics. With output schema existing, no need to detail return values. Complete for the tool's complexity.
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 covers all parameters with descriptions (100% coverage). Description adds minor extra context (e.g., cost per enrich_top, default for include_platforms), but not substantial beyond schema.
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?
Clearly states it finds outreach targets based on gap analysis, ranking priority and secondary domains. Distinct from sibling tools (backlinks, gap_analysis, releases) by combining both analyses.
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?
Explicitly says 'Use 2-3 competitors' and describes the ranking logic, giving clear context. Does not include explicit when-not-to-use, but the purpose is clear enough.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
List the Common Crawl releases the API can query. Does not count against any quota. Use a release id with the backlinks tool to query a specific snapshot.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
| Name | Required | Description |
|---|---|---|
| releases | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint, idempotentHint, destructiveHint. The description adds that it does not count against quota, which is valuable behavioral context beyond annotations. No contradictions.
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?
Two concise sentences, front-loaded with purpose, no superfluous words. Every sentence adds value.
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?
Tool is simple with no parameters and an output schema. The description fully explains purpose, quota impact, and how to use the output with a sibling tool. Complete for the tool's complexity.
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?
No parameters exist, so baseline is 4. The description adds no parameter info, but none is needed since there are no parameters.
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 lists Common Crawl releases the API can query, with a specific verb and resource. It distinguishes from siblings by mentioning using a release id with the backlinks tool.
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?
Explicitly states it does not count against quota, and advises to use a release id with the backlinks tool to query a specific snapshot, providing clear context for when to use this tool versus alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
backlink_changesbacklinksgap_analysisgap_outreach_targetsreleases
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