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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds substantial behavior: it lists the exact fields returned (event id, type, UTC start, title, fiscal period, status, availability of transcript/audio/slides), states ordering ('newest first'), and highlights that conferences have no fiscal quarter. This goes beyond the annotations without contradicting them.

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 sentences, each earning its place: the first states purpose and scope, the second enumerates output fields, the third gives crucial routing guidance. No filler, clear ordering, and the most important information (scope and distinction) is front-loaded.

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 no output schema, the description fully compensates by enumerating every return field and the ordering. It also explains the critical nuance that conferences lack a fiscal quarter, which is essential for correct follow-up calls, and names the exact sibling to use. Nothing an agent needs to invoke or correctly interpret the result 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% — all three parameters (ticker, limit, eventType) have detailed descriptions including defaults and valid values. The description adds no additional parameter-level meaning (e.g., it doesn't introduce the eventType filter or clarify limit clamping beyond what the schema says). 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 ('List') and resource ('a company's recent investor events'), enumerates the event types covered (earnings calls, conferences, investor/analyst days, shareholder meetings), and explicitly contrasts with sibling tools GetEarningsCallEvent and GetInvestorEventTranscript, making the tool's scope unmistakable.

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 guidance: 'Conferences have no fiscal quarter, so use the event id with GetInvestorEventTranscript to read one rather than GetEarningsCallEvent (which is keyed by fiscal quarter and earnings-only).' This directly tells the agent when not to use an alternative. It does not cover other siblings like GetUpcomingInvestorEvents, but the most relevant distinction is clear.

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