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

Annotations already establish the safe read-only, idempotent profile. The description adds meaningful behavioral detail beyond that: the hard 15-day truncation, that the served window is reported back in fromDate/toDate, and the continuation pattern for longer ranges.

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-loads the tool's purpose, then the range constraint and pagination rule, then the argument reference. The Args section slightly repeats the 14-day maximum already stated in the prose, a minor redundancy.

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?

Given three optional parameters, no output schema, and 0% schema description coverage, the description covers the essential inputs, the truncation behavior, and the response window metadata. It could say more about the returned earnings fields, but the core calling information is present.

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 0%, so the description carries the full burden and does so well. It documents all three parameters with formats, defaults, the 14-day maximum, and an exchange-filter example, adding substantial meaning beyond the bare schema.

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: returns upcoming earnings dates across all stocks for a date range. The phrases 'upcoming' and 'across all stocks' implicitly distinguish it from past-earnings and single-ticker siblings, but no sibling is named explicitly.

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 clear operational context: at most 15 days per call, and how to continue with multiple calls for longer periods. It does not name an alternative tool or state when another earnings-calendar sibling would be preferable, so it stops short of full when-to-use guidance.

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