Using Heavy Mcps

Token-Efficient MCP Usage via MCPorter

When working with MCPs that return large payloads—like Sanity queries with full document content or Brain vault searches with entire file contents—you can route these calls through mcporter outside of chat, trim the output with jq, and feed only the compact result back to the model. This avoids the 20–40k token bloat that comes from loading full responses into context.

When to Use This Pattern

Use mcporter + jq when:

• Large responses: Sanity queries returning full documents, Brain vault searches with file contents
• Repeated queries: You need the same data multiple times and only care about specific fields
• Field filtering: The MCP returns 50 fields but you only need 3
• Chained operations: Multiple MCP calls where each bloats context
• List operations: Getting 100 items but only needing titles and IDs

Don't use this pattern when:

• Exploring unfamiliar data (let Cursor call MCP directly to see full structure)
• Response is already small (

### Pattern 2: Embedding in other Cursor rules

Add mcporter commands to rules that need specific data:

```markdown
## Portfolio Context

When discussing portfolio work, use this to fetch current project list:

bunx mcporter call 'Sanity Developer.query_documents(
  resource: {projectId: "xyz", dataset: "production"},
  query: "*[_type == \"project\"]"
)' | jq '[.[] | {title: .title, role: .role}]'

Pattern 3: Save as shell alias

Add to your .zshrc for frequently-used queries:

alias portfolio-list='bunx mcporter call '"'"'Sanity Developer.query_documents(
  resource: {projectId: "xyz", dataset: "production"},
  query: "*[_type == \"project\"]"
)'"'"' | jq "[.[] | {title: .title, slug: .slug.current}]"'

Then just run: portfolio-list

When to Just Use Cursor's MCP Calls

Let Cursor call MCPs directly when:

• Exploring: You don't know the response structure yet
• Small responses: The data is already compact
• Interactive filtering: You want to iteratively refine what you're looking for
• One-off questions: Not worth the setup overhead

The mcporter pattern is for repeatability and token efficiency, not every MCP interaction.

Avoiding Token Waste on Failed Calls

Set timeouts to fail fast:

# Don't wait forever for a hung MCP call
bunx mcporter call 'Brain.vault(action: "search", query: "test")' --timeout 10000

Default timeout is 30 seconds. For slow operations, increase it. For quick checks, decrease it.

Check auth before expensive queries:

# Verify authentication status
bunx mcporter config get "Sanity Developer"

# If auth is required, do it once
bunx mcporter auth "Sanity Developer"

This prevents loading huge error messages into context when auth fails.

Use --output json for programmatic error handling:

bunx mcporter call 'Brain.vault(action: "search", query: "test")' --output json

The structured envelope makes it easier to detect failures without loading full error traces into context.

Debugging Tips

Check available MCPs:

bunx mcporter list

See tool signatures and schemas:

bunx mcporter list Brain --schema
bunx mcporter list "Sanity Developer" --schema

Test without jq first:

bunx mcporter call 'Brain.vault(action: "search", query: "test")'

Then add jq filtering once you see the structure.

Format jq output for readability:

... | jq '.'
# vs compact:
... | jq -c '.'

Real-World Token Savings

Before (direct MCP call in chat):

• Sanity query for 10 projects with full content: ~25,000 tokens
• Brain vault search returning 5 notes: ~15,000 tokens

After (mcporter + jq):

• Same Sanity query, titles/IDs only: ~500 tokens
• Same vault search, metadata only: ~300 tokens

Savings: 95%+ reduction for typical filtered queries.

Additional Resources

Official mcporter documentation: Available via Context7 at /steipete/mcporter

Key docs to reference:

• Call syntax and examples: mcporter/docs/call-syntax.md
• Tool calling guide: mcporter/docs/tool-calling.md
• Configuration: mcporter/docs/config.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: nweii
• Source: nweii/agent-stuff
• License: MIT

Install and usage instructions live in the source repository linked above.