Start period date

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description doesn't need to state side effects. It adds the return format (YYYY-MM-DD) and that it can return either the accounting's start date or that of a given period abbreviation. This goes beyond the annotations but could be slightly clearer about 'the accounting'.

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?

A single, front-loaded sentence that states the action and output format without any filler. Every word contributes to understanding the tool's purpose.

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 straightforward read-only tool with parameters fully described in the schema, the description covers the core return value and input types. However, 'of the accounting' is slightly ambiguous (whether it means the fiscal year start or current period start), and no error behavior is mentioned. Given the presence of schema and annotations, this is a minor gap.

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?

The input schema covers 100% of parameter descriptions, providing details for 'doc' and 'period' including abbreviations and date ranges. The description adds little beyond the schema, so the baseline of 3 is appropriate.

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 uses the specific verb 'Return' with a clear resource 'start date' and output format 'YYYY-MM-DD'. It distinguishes from sibling banana_end_period by explicitly focusing on the start date, making its purpose unambiguous.

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 context is clear: this tool is for obtaining the start date of an accounting period or a given abbreviation like 'Q1'. However, it does not explicitly mention when not to use it or reference alternatives, though the sibling banana_end_period implies complementary usage. No exclusions are stated, but the purpose is evident.

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