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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral context: an empty trades array is valid rather than an error, which prevents the agent from misreading a zero-result response. It does not mention auth needs 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 compact sentences, front-loaded with the core action, followed by the empty-result caveat and the alternative routing. No filler, and each clause earns its place.

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?

With an output schema present, return values need not be explained, and annotations cover the safety profile. The description supplies purpose, empty-result semantics, and sibling routing, which is nearly everything needed to invoke it correctly; it could add a note on filtering options (taker_only, filter_amount) to be fully complete.

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 all seven parameters are already documented in the schema. The description reinforces the market condition ID scope but adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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), resource (public Polymarket trades), and scope (for one market condition ID), and explicitly names the siblings it is not (polymarket_market_detail, polymarket_public_data). An agent can distinguish this from the many polymarket_* tools without opening a schema. The mention of 'market condition ID' is slightly narrow given event_id is also supported, but it is not misleading.

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?

Provides explicit routing to alternatives: use polymarket_market_detail for the market and polymarket_public_data for broader public records. This gives clear when-to-use-which context, though it stops short of stating conditions under which this tool should not be used.

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