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

Annotations already cover the read-only, non-destructive profile, and the description adds substantial context beyond them: data provenance (scraped from the company's IR website), a partial-coverage caveat with a stated way to interpret empty results, and the projection behavior for the next earnings call labelled as an estimate. This is exactly the extra context annotations cannot express.

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?

Front-loaded with what the tool returns, followed by scope, then the alternative-tool routing. It is dense and slightly long-winded (the earnings-call projection sentence is intricate), but no sentence is filler.

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 supplies ordering ('soonest first'), scope limits (future only), empty-result semantics, and the extra next-earnings-call field. Nothing an agent needs in order to call this correctly 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% and all three parameters are documented in the schema, including the 'Event' fallback type for unclassified labels. The description restates the optional event-type filter but adds no syntax or format detail 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 verb and resource ('Get upcoming investor-relations events for a stock') and enumerates the concrete event kinds returned, then explicitly disclaims the past-events territory owned by ListInvestorEvents / GetInvestorEventTranscript. An agent can distinguish it from GetEarningsCallEvent and the transcript tools without opening a schema.

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?

Names the alternatives and the condition that selects them: 'Only future events are returned; for past events and their transcripts use ListInvestorEvents / GetInvestorEventTranscript.' It also gives filtering guidance ('optionally filtered by event type') and tells the agent how to read an empty answer.

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