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

With no annotations and no output schema, the description carries the burden, and it does so well by enumerating the returned payload: outcomes/prices, bid/ask/spread, volume, liquidity, CLOB midpoint, 24h high/low/change, and a summary line. It still omits read-only affirmation and error behavior for invalid ids, which is why it isn't a 5.

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?

A single front-loaded sentence that names the resource first and then lists return contents after a colon. Every element earns its place; no filler or repetition.

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?

For a one-parameter read tool with no output schema and no annotations, the return-content inventory makes the definition largely self-sufficient. Minor gaps remain around failure modes and freshness of the quoted prices.

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% and the schema already documents 'Market id (numeric) or slug'; the description repeats rather than extends that. Baseline 3 applies since the schema does the work and the description adds no format, validation, or ambiguity guidance.

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 ('Details for one Polymarket market'), plus the exact lookup key ('numeric id or slug'). The singular, identifier-driven framing cleanly separates it from the list-oriented siblings (search_markets, top_markets, biggest_movers).

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?

Usage is only implied: the agent can infer 'use when you already have a market id/slug and want detail.' No alternative is named and no when-not condition is given, so it falls short of the explicit routing seen in stronger definitions.

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