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

Annotations already declare readOnlyHint and openWorldHint, so safety and open-world behavior are covered. The description adds that results are 'current' and limited to 'one public section', which is useful framing, but says nothing about freshness window, result counts, or authentication.

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 tight sentence with the resource and the input constraint front-loaded; 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?

With an output schema present, return values need no explanation, and the read-only annotation covers the safety profile. The remaining gap is operational detail such as how many headlines are returned or how 'current' is defined.

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% and already enumerates the documented section slugs, so the schema does the heavy lifting. The description adds a provenance constraint ('must come from polygon_sections') that overlaps with the enumerated list rather than extending it, so baseline 3 is appropriate.

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+resource ('Current Polygon headlines for one public section') and scopes it to a single section, which separates it from polygon_news/polygon_article feed-style siblings. It explicitly points to polygon_sections for valid inputs, though it does not distinguish itself from polygon_news by name.

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?

Gives a concrete prerequisite: the section value 'must come from polygon_sections', which routes the agent to the sibling that produces valid slugs. It does not state when to prefer this over polygon_news or polygon_article, so no explicit exclusions are offered.

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