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 partly covered. The description adds real behavioral context beyond that: unsupported query keys are ignored, arbitrary URLs or route keys are rejected, and it places no orders. Input-validation behavior and the no-side-effect guarantee are useful additions.

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?

Three dense sentences, front-loaded with the core action and scope, then parameters, then routing. No filler. Slightly information-heavy but 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?

An output schema exists, so return values need not be described. For a generic allowlisted-route dispatcher with nested objects, the description covers scope, validation behavior, and where to find route-specific payload docs. Adequate and near 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 coverage is 100%, so the baseline is 3. The description goes further by explaining the division of labor: params fills route template placeholders and query supplies route-specific filters, with unsupported query keys ignored. This clarifies intent beyond the schema's per-field text.

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 (public Gamma JSON for an allowlisted Polymarket route key), and names the sibling tools (polymarket_markets, polymarket_events) it is not. An agent can distinguish this raw-route dispatcher from the normalized market/event tools without opening schemas. It is a clear purpose, though the generic dispatcher nature keeps it from being maximally sharp.

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?

Explicitly routes the agent: use polymarket_markets for normalized market browsing or polymarket_events for event rows, and consult route-specific docs for other payloads. This gives clear alternatives and a when-to-use signal. It stops short of a full when-not/exclusion matrix but covers the key decision points.

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