Contact Labels: List Labels

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint, openWorldHint), so the bar is lower, and the description goes beyond them by disclosing the exact endpoint, the required auth header ('api-access-token'), and a data-handling note about Persian/Arabic-Indic digits being accepted unchanged. It does not mention pagination or result ordering.

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?

Purpose is front-loaded in the first clause, followed by the route, auth, and locale note. It is compact and mostly earns its space, though restating the raw HTTP path is somewhat redundant for an agent that already has the schema.

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 two-parameter read-only list tool with no output schema and rich annotations, the description covers purpose, auth, endpoint, and a locale caveat that could matter for identifier input. Return-value shape is the only unaddressed item, and no output schema exists to carry it.

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 description coverage is 100% and both parameters carry their own descriptions, so the schema does the heavy lifting. The description adds nothing about account_id or contact_identifier formats, so the baseline of 3 applies.

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?

States a specific verb and resource ('List the labels of a contact'), which is clearly distinct from the many sibling list tools and from the write counterpart gapify_set_contact_labels. It never names that sibling to sharpen the contrast, so it stops short of the top band.

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 implied by the name and the purpose sentence — this is the read-side of contact label management — but the description gives no explicit when-to-use or when-not-to-use guidance and never points to gapify_set_contact_labels or gapify_list_contacts as alternatives.

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