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by io.github.pipeworx-io

Polymarket–Kalshi Spread

polymarket_kalshi_spread
Read-onlyIdempotent

Cross-venue spread between Kalshi and Polymarket for the same resolving question. The two venues sometimes price the same outcome 2-25pp apart because their participant pools differ — when the bet shapes are equivalent that delta is a real signal, when they aren't the tool says so. TWO MODES: (1) topic — 10 pre-mapped macro shortcuts ("fed", "btc", "cpi", "gdp", "sp500", "recession", "next_pope", "next_uk_pm", "next_israel_pm", "2028_president") auto-fetch the matching event on each venue. (2) explicit kalshi_event_ticker + polymarket_event_slug for custom pairings — BOTH modes run the identical token-overlap matcher, so the same disclosures apply to both. RESPONSE: each venue's leg-by-leg prices (raw probability 0-1) plus matched spread[].top_spreads_pp (Kalshi − Polymarket) where the same outcome shows up on both sides. SAFETY FIELDS: compatibility_warning is a sentence and compatibility_codes[] the machine-readable form; BOTH can be non-empty on returned pairs, so read them even when matched_pairs>0. Codes: event_subject_mismatch (the two event titles share no subject words — probably not the same question), temporal_mismatch (they resolve in different months), temporal_alignment_unknown (the resolution month could not be parsed on one or both sides — NOT the same as confirmed-aligned; check each event's close/strike date yourself), non_equivalent_bet_shapes, no_candidate_pairs, unclassified_legs_excluded, pairing_unverified (set in EITHER mode whenever pairs are returned: the legs were matched by keyword and word overlap, not a shared resolution source). Each entry in top_spreads_pp carries its own flags[] (temporal_mismatch, temporal_alignment_unknown, event_subject_mismatch, low_token_overlap). A leg whose metric_type or match_subtype is "unknown" is NEVER paired — those comparisons land in spread.skipped_unclassified and, when the wording lined up, in spread.low_confidence_pairs[] for inspection only. temporal_alignment{polymarket_month,kalshi_month,aligned} tells you whether the two events resolve in the same calendar period, in EITHER mode; null means it could not be computed (see temporal_alignment_unknown), not that the two sides align. spread.fees_note is a standing disclosure: Kalshi charges per-contract trading fees, Polymarket does not, and this tool does not model Kalshi's fee schedule — every spread_pp is gross, not a net tradeable edge. skipped_cross_type / skipped_cross_subtype counters expose how many leg-pair comparisons were dropped (cross-type = metric_type mismatch like MoM vs YoY; cross-subtype = inequality mismatch like cum_ge vs cum_le). Real cross-venue spreads are rarer than the macro-shortcut list suggests — most pre-mapped topics return compatibility_warning today; pre-mapped ≠ tradeable.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
topicNoPre-mapped: fed | btc | cpi | gdp | sp500 | recession | next_pope | next_uk_pm | next_israel_pm | 2028_president
kalshi_event_tickerNoExplicit Kalshi event ticker, e.g. "KXFED-26OCT". Overrides the topic-mapped Kalshi side.
polymarket_event_slugNoExplicit Polymarket event slug, e.g. "fed-decision-in-june-825". Overrides the topic-mapped Polymarket side.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed1 schema field changed
    • addedInput schema / examples
      Added value: +[
+  {
+    "topic": "fed"
+  },
+  {
+    "topic": "btc"
+  }
+]
  2. Added

TDQS

A4.2/5.0
Behavior5/5

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

With readOnly/openWorld/idempotent annotations already covering safety, the description goes well beyond them by disclosing the matching algorithm's caveats, compatibility codes, per-pair flags, skipped_unclassified legs, gross-vs-net fee handling, and the meaning of null temporal_alignment. It repeatedly clarifies that a non-empty compatibility field can appear even when pairs are returned, so the agent won't over-trust matched_pairs.

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

Conciseness3/5

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

The content is almost always substantive and the front matter is organized around TWO MODES / RESPONSE / SAFETY FIELDS, but it is long and repeats caveats (temporal_alignment_unknown is explained twice, and the compatibility warning readability advice appears both in the safety-fields sentence and in the closing warning). This is appropriate for a complex tool but not concise.

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?

Because there is no output schema, the description carries the full burden of explaining the response, and it does: per-leg prices, top_spreads_pp with flags, skipped_unclassified counters, compatibility codes, temporal_alignment semantics, and the fee disclosure. For a tool with zero required params and no output schema, the agent has enough context to call it correctly and interpret results.

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% and each parameter already has a description, so the baseline is 3. The description adds real semantic value by explaining that topic is a pre-mapped shortcut, the ticker/slug arguments are explicit overrides, and that both parameter modes execute the same token-overlap matching and disclosures—this is beyond the schema.

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

Purpose4/5

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

The description opens with a clear statement of scope: 'Cross-venue spread between Kalshi and Polymarket for the same resolving question' and details two retrieval modes, so the agent knows what the tool computes. It does not explicitly differentiate from the closely named sibling polymarket_arbitrage or name alternatives, which keeps it a step below a fully distinguished definition.

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?

The description gives explicit mode-selection guidance: use the 10 pre-mapped topic shortcuts or supply explicit kalshi_event_ticker + polymarket_event_slug for custom pairings, and notes that both run the same matcher. It also warns that pre-mapped topics often return compatibility warnings and 'pre-mapped ≠ tradeable', but it never states when to prefer a sibling tool such as polymarket_arbitrage.

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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TDQS

A3.5/5.0
Disambiguation2/5

Several tools have overlapping or near-identical purposes, e.g., ask_pipeworx and ask_pipeworx_beta are explicitly described as currently equivalent, and polymarket_arbitrage, polymarket_edges, and bet_research all target prediction-market opportunities. Descriptions help somewhat, but boundaries remain fuzzy for agents.

Naming Consistency2/5

Tool names follow no consistent convention: some are verb-first (get_status_cat, remember), others are noun phrases (entity_profile, deep_research), and many use domain prefixes (ask_pipeworx, polymarket_*, pipeworx_feedback). While snake_case is maintained throughout, the structural pattern is mixed and unpredictable.

Tool Count2/5

At 33 tools, the server is well beyond the typical well-scoped range (3-15). The count is inflated by multiple overlapping meta-tools and unrelated utility groups (HTTP cats, Pipeworx research, prediction markets, memory, subscriptions), making the set feel bloated rather than focused.

Completeness2/5

The server name 'httpcat' implies HTTP status-cat functionality, but only 2 of 33 tools serve that purpose, leaving the named domain largely uncovered. As a general-purpose data server, the collection still has gaps (e.g., no direct trading, no general web search) and appears to be a random assortment of features rather than a coherent product.

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