hail

Official

by hail-hq

Overview Schema Source Related Servers Discussions Admin

Python

Hybrid

Look up a contact

lookup_contact

Read-onlyIdempotent

Find a contact by name, email, or phone fragment. Resolve a person to their phone_e164/email BEFORE calling place_call, send_sms, or send_email — do not guess a contact's number.

Instructions

Find a contact by name, email, or phone fragment. Resolve a person to their phone_e164/email BEFORE calling place_call, send_sms, or send_email — do not guess a contact's number.

    Returns up to 10 matches, same item shape as ``list_contacts``.

    Example:
        lookup_contact(query="maya")

Input Schema

Name	Required	Description	Default
`query`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.29.0Oct 21, 2026

TDQS

A4.7/5.0

Behavior4/5

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new behavior: a hard cap of up to 10 matches and a reference point for item shape (same as list_contacts). It does not say what happens on zero matches or whether matching is exact vs substring beyond 'fragment,' which keeps it short of a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short, front-loaded sentences plus a one-line example; the resolution precondition precedes the return-value note, and nothing is redundant with the title or schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter lookup with an output schema, the description supplies the only things the schema can't: accepted query forms, result cap, cross-tool sequencing, and return shape. Nothing an agent needs in order to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% for the single `query` param, so the description must compensate; it does by enumerating the three accepted key types (name, email, phone fragment) and showing a usage example. It still doesn't specify matching semantics (case sensitivity, substring vs prefix) or format expectations for each key type.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Find a contact'), names the accepted lookup keys (name, email, phone fragment), and distinguishes it from list_contacts and create_contact by describing resolution rather than enumeration or creation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit precondition: resolve to phone_e164/email BEFORE calling place_call, send_sms, or send_email, plus the negative instruction 'do not guess a contact's number.' It names the concrete alternative risk (guessing) and the sibling tools it feeds into.

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