get_account_by_email

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

With no annotations, the description carries the full burden. It discloses that account details are returned 'if found', which hints at conditional behavior, but does not specify what happens when no account exists (e.g., empty response, error). It also omits any side effects or authentication requirements, though reads are likely safe.

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 a single, front-loaded sentence that directly states the action and expected result. Every word contributes meaning, with no redundant or filler content.

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 one-parameter lookup tool, the description covers the essential purpose and return outcome. It would benefit from specifying the not-found behavior and possibly a brief contrast with get_account, but these are minor gaps given the tool's low complexity.

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 0% and the description merely restates the parameter name ('email address'), adding no extra detail about format, validation, case-sensitivity, or expected input. Since the schema only declares a string type, the description fails to compensate for the low coverage.

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 a specific verb ('Look up') and resource ('FastSpring customer account') with a clear query method ('by email address'). It distinguishes itself from siblings like get_account, which likely uses an account ID, and get_account_orders, which focuses on orders.

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 when an email is known, but does not explicitly state when to prefer this tool over alternatives such as get_account (likely by ID) or list_orders_by_email. No exclusions or alternative references are provided, so guidance remains implicit.

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