Get Payee Locations By Payee

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint. The description reinforces 'read-only' and adds the important behavioral detail that results are empty for payees never used in the mobile app. No contradiction with annotations.

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?

Two concise sentences with no extraneous information. The first sentence states the action and read-only nature; the second adds use case and a key behavioral note. Every sentence serves a 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 simple read-only lookup tool with an output schema (not shown here), the description covers what it does, when to use it, and a crucial behavioral nuance. No additional context is needed.

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 parameters are fully documented in the input schema. The description does not add extra meaning beyond what the schema provides, hitting the baseline for a well-covered 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 clearly states the action ('Get all recorded GPS locations'), resource ('for one payee'), and a specific use case ('confirm which physical merchant an ambiguous payee refers to'). It distinguishes from sibling tools like list_payee_locations by specifying 'for one payee'.

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 provides clear context on when to use the tool ('confirm which physical merchant an ambiguous payee refers to') and notes a behavioral outcome ('empty for payees never used in YNAB's mobile app'). It does not explicitly compare to alternatives, but the purpose is well framed.

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