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

Annotations declare readOnlyHint=true, so the read-only nature is already known. The description adds value by enumerating the exact output fields (event date, session, confirmation status, fiscal period, importance, EPS estimate, implied-move) and the adjustable window, which goes beyond the annotation without contradicting it.

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?

The description is three concise sentences: purpose, return fields, and parameters. It is front-loaded with the core function, avoids redundancy, and every sentence adds useful information with no fluff.

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 calendar tool with full schema coverage and an explicit list of return fields, the description is largely complete. It may lack details on pagination or max symbols, and it does not differentiate from siblings, but overall it gives the agent enough to invoke it 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 100%, so the schema already documents all four parameters fully. The description reinforces the meaning of the window and filters but adds no new syntax or format details beyond what the schema provides, earning the baseline score.

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 it returns an upcoming earnings calendar over a configurable window, listing the specific fields returned. It has a clear verb+resource focus ('calendar') and is easily distinguishable from many siblings, though it does not explicitly compare with similar earnings tools like get_earnings or get_earnings_screener.

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 description implies usage by describing the forward window and available filters (symbols, importance), but it does not explicitly state when to choose this tool over alternatives. No exclusions or alternative tool mentions are provided, leaving the choice to the agent based on the name and context.

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