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

Beyond the read-only and idempotent annotations, the description discloses the actual calculation rules: the 30-day 83(b) deadline with business-day rolling, and the QSBS 3/4/5-year exclusion milestones with a July 4, 2025 acquisition cutoff. These details materially help an agent understand the tool's behavior and trust its outputs.

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 front-loaded with the core purpose and then compactly explains each date parameter. Every sentence carries substantive information, including the sibling-tool routing and calculator link, with no 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?

For a low-complexity date calculator with full schema coverage and clear annotations, the description is largely complete. The only notable gap is that it does not describe the return format or output shape, which is not covered by an output schema.

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 coverage is 100%, so the schema already documents all three parameters. The description still adds useful semantic depth for `stock_grant_date` and `qsbs_acquired_date` by explaining the exact deadlines and milestones each date triggers, though it does not add anything about `as_of_date` beyond the 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?

The description states that the tool returns key US equity tax dates, specifically 83(b) election and QSBS holding-period milestones. It distinguishes itself from the sibling `qsbs` tool by directing agents to use `qsbs` for the dollar exclusion on a sale, making the boundary clear.

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?

It explicitly says to provide either or both date parameters and names the alternative `qsbs` tool for a different purpose. This gives an agent clear routing guidance between this date calculator and the QSBS dollar-exclusion tool.

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