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

Annotations provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is already covered by structured data. The description adds that it returns 'reported or scheduled' events, which is useful context. However, it doesn't disclose pagination behavior, ordering of results, or whether both reported and scheduled events are mixed in the same response—modest added value beyond annotations.

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?

One efficient sentence, zero filler, appropriately front-loaded with the core purpose. It earns its single sentence. Minor deduction: it could have added a usage note about when to prefer this over market_fundamentals without hurting conciseness.

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 read-only list tool with strong annotations (read-only, idempotent, open-world) and an output schema, the description is reasonably complete. It identifies the core inputs (date range + ticker) and the data returned (earnings events). Given the availability of an output schema, this is adequate for an agent to select and invoke the tool correctly.

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 only 25% (only symbol has a meaningful description per the coverage calculation, though limit/date params have inline descriptions too). The description compensates by naming which params matter (date range, ticker filter) and their roles. It clarifies that dates are a range and the symbol is optional, adding meaning beyond the bare schema. Slight gap: it doesn't explain the interplay between start/end defaults when one is omitted.

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?

The description clearly states the tool returns earnings events (reported or scheduled) in a date range with an optional ticker filter. It uses a specific verb+resource and distinguishes it from siblings like market_quote and market_fundamentals. It's clear but doesn't explicitly contrast with the news or macro siblings, though the earnings focus is self-evident.

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?

The date-range and optional ticker filter are described, giving a clear idea of what inputs are expected. However, there is no 'when to use vs. alternatives' guidance, no mention of defaults (like if start_day defaults to something), and no note of whether reported vs scheduled events can be distinguished or filtered independently.

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