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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new context: results come from the OpenAccountants tax calendar, include both upcoming dates and recurring rhythms, and that the response marks jurisdiction_source.

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 resource and scope, then uses compact example queries to convey intent efficiently. Slightly dense but every clause carries information; no filler sentences.

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?

An output schema exists, so return values need not be detailed, yet the description still summarizes the output shape. For a two-parameter read tool this covers everything an agent needs 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 coverage is 100%, and the description's jurisdiction note ('can omit jurisdiction') largely restates what the schema already documents. The pointer to the jurisdiction_source response field is a small addition, but the schema is doing most of the work.

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 resource ('Filing and payment deadlines for a country or US state') with example phrasings that map directly onto the tool's intent. No sibling in the list competes for this operation, so the agent can distinguish it immediately.

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 illustrative queries ('when is my tax return due', 'when do I file VAT') make the intended use unambiguous, and it notes that signed-in users with a saved home jurisdiction can omit the parameter. It stops short of naming alternatives or explicit exclusions, but none are needed since no sibling overlaps.

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