Find person by email

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-reach are covered. The description adds 'Returns the full person record,' which is useful because no output schema exists, but omits not-found behavior (error vs empty result) and any auth or rate-limit context.

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 short sentences with zero filler; the lookup scope is front-loaded and the return behavior follows immediately. Every clause earns its place.

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 one-parameter, read-only lookup with annotations and no output schema, the description covers what it does, the exactness of the match, and the shape of the return. The remaining gap is the not-found/empty-result contract, which an agent would want before calling.

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?

There is a single required parameter with 0% schema description coverage, so the description must carry the meaning. It does add the important semantic that matching is EXACT (not partial), but says nothing about case sensitivity, whitespace trimming, or what happens with a non-matching address.

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 names a specific verb (look up) and a precise resource/scope (one contact by exact email address), which implicitly contrasts with the multi-result sibling search_people. It is clear and unambiguous, but it never names or explicitly contrasts with an alternative tool, so it stops short of the 5 tier.

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?

Usage is only implied: the phrase 'by exact email address' suggests this is the single-record lookup path when the email is known, versus a search tool. There is no explicit when-to-use statement, no exclusion (e.g. partial or fuzzy matching), and no routing to search_people.

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