getPersonByEmail

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does add a key behavior: returning the first matching contact, which is not trivial. However, it lacks details about permissions, not-found behavior, or whether the result is a full person object. The verb 'look up' suggests a read operation, but this is implicit.

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 two short, focused sentences with no redundant words. Every phrase earns its place: the lookup action, the identifier, the return behavior. It is an exemplary model of conciseness for a simple tool.

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?

Given that this is a simple lookup tool with one fully documented parameter and no output schema, the description covers the essential aspects: what to provide (email) and what to expect (first matching contact). It does not mention return format, but 'contact' is sufficiently clear for most uses. The description is nearly complete, though a bit more detail about the return object would fully round it out.

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 schema already describes the email parameter with 100% coverage ('Email address to look up'), and the description adds little beyond that phrase. No additional parameter-level details are provided, so the description does not significantly enhance understanding of the parameter 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 uses a specific verb ('look up') and resource ('a person by email address'), clearly stating the tool's function. It also adds the behavior of returning the first matching contact, which distinguishes it from list-style tools like listPeople. The name and description together leave no ambiguity about purpose.

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 when to use the tool (when you have an email address and need a person), but it does not explicitly mention alternatives or exclusions. There is no guidance on when to use this over getPerson, checkDuplicate, or listPeople, so it relies on the name and reader inference.

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