snap_list_segments

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

Annotations already declare readOnlyHint=true, so '(read-only)' adds nothing. The description does add genuine behavior beyond annotations: default ordering is largest-first, and each segment is reported with size and status. It omits pagination/limit behavior and whether results are account-scoped, which leaves notable gaps.

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?

A single tight sentence with the verb and resource front-loaded and no wasted clauses. The parenthetical list partially duplicates the source_type enum, a minor redundancy.

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?

With no output schema, the description usefully states that rows include size and status. However, for a 4-parameter listing tool with 0% schema coverage, it leaves out result paging, the default/maximum limit, and whether ad_account_id scopes the listing or is optional filtering.

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 0%, so the description must carry parameter meaning and largely fails. The enumerated segment types loosely map to the source_type enum, but limit, min_size, and ad_account_id (all optional, undocumented) get no explanation of default, cap, or scoping semantics.

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+resource ('List audience segments') and enumerates the segment categories (customer lists, pixel, engagement, lookalike), plus what each row carries (size, status) and ordering (largest first). An agent can tell this apart from listing tools for ads, pixels, or catalogs. It does not explicitly differentiate from size/insights siblings, so not a 5.

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 only usage signal is the parenthetical '(read-only)', which restates the annotation rather than giving guidance. There is no statement of when to pick this over snap_audience_size or snap_audience_insights, and no prerequisites or exclusions are mentioned.

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