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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds real behavioral context beyond that: quote fields are only present 'when available', and there is an explicit precedence ordering among the identifier arguments. It does not cover auth or rate limits, keeping it short of 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?

Two sentences, front-loaded with the action and return shape, followed by argument resolution and sibling routing. No filler and nothing redundant with structured fields.

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 values need not be re-explained, and the description correctly focuses on what it can add: what the endpoint is, how to select a market, and when to route elsewhere. Nothing needed to invoke it correctly 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 the baseline is 3. The description goes beyond the schema by defining the conflict-resolution rule between the three identifier params (slug beats condition_id), which the schema's one-line field descriptions do not convey.

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 ('Fetch') and resource ('one normalized Polymarket Gamma market'), then enumerates the returned fields (outcome prices, liquidity, volume, quote fields). It explicitly distinguishes itself from polymarket_clob_market and polymarket_event_detail, so an agent can pick it without opening either 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?

Names the two alternative siblings and the condition that selects each ('CLOB market metadata' vs 'the containing event'), which effectively tells the agent when this tool is the right choice. It also resolves the multi-argument case by stating precedence (slug, then condition_id).

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