Polymarket MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While it mentions 'real-time price changes' and provides an example, it doesn't describe what 'subscribe' entails operationally - whether this creates a persistent connection, polling mechanism, or webhook. It doesn't mention authentication requirements, rate limits, error handling, or what happens when subscription ends. The description adds some context but leaves critical behavioral aspects unspecified.

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 appropriately sized with three sentences. The first sentence states the core purpose, the second provides source context and related tools, and the third gives an example. Each sentence adds value, though the structure could be slightly improved by front-loading the example more clearly. There's minimal wasted text.

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 this is a subscription tool with 2 parameters (100% schema coverage) but no annotations and no output schema, the description is moderately complete. It covers the basic purpose, parameter sources, and related tools, but lacks critical information about subscription behavior, return values, error conditions, and operational constraints. For a real-time subscription tool, more behavioral context would be expected.

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 the schema already fully documents both parameters (market_ids and callback_type). The description adds minimal value beyond the schema: it provides an example format 'market_ids=[conditionId]' and mentions the source of market IDs, but doesn't explain parameter interactions or provide additional semantic context. This meets the baseline 3 when schema does the heavy lifting.

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's purpose: 'Subscribe to real-time price changes by market condition IDs' with a specific verb ('Subscribe') and resource ('real-time price changes'). It distinguishes from siblings by mentioning 'market condition IDs' and referencing specific sibling tools (list_markets, etc.), but doesn't explicitly differentiate from similar subscription tools like subscribe_market_resolution or subscribe_orderbook_updates.

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 provides clear context for when to use this tool: when needing real-time price updates for specific market condition IDs obtained from list_markets/list_active_markets/get_market_by_slug. It also mentions using get_realtime_status to inspect events, providing related tool guidance. However, it doesn't explicitly state when NOT to use it or when to choose alternatives like get_current_price for one-time queries.

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