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

Annotations already declare readOnlyHint=true, so safety is covered. The description usefully adds that coverage spans both upcoming and recent IPOs (forward- and backward-looking) and names the upstream Finnhub endpoint, but says nothing about pagination, result volume, or rate limits.

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 clauses with the resource front-loaded and the data scope immediately after; the REST endpoint hint is a single trailing token. Nothing is wasted.

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 simple two-parameter read tool with no output schema and readOnlyHint already declared, the description supplies what an agent needs to invoke it: subject matter, temporal scope, and endpoint. Only minor gaps remain around result shape and any range limits.

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% — both 'from' and 'to' are documented with format and required status. The description's 'for a date range' adds no syntax or boundary detail (e.g. max span, inclusive/exclusive endings) beyond the schema, so baseline 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 resource (IPO calendar) and scope (date range, upcoming and recent IPOs), which is easy to separate from finnhub_earnings_calendar and other siblings by name. It stops short of explicitly contrasting itself with the earnings calendar, but the resource is unambiguous.

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 — an agent can infer this is for retrieving IPO listings over a window, but the description names no alternatives, prerequisites, or conditions for choosing it over the earnings calendar. No when-not guidance is given.

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