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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. Beyond that, the description usefully discloses the two distinct result sources (Google catalog vs. account-owned lists) and that the output is IDs intended for a follow-up mutation. Pagination or result-count limits are not mentioned.

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 compact sentence with two coordinate clauses plus a return-value clause; the primary search behavior is front-loaded and nothing is redundant or padded.

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 only two optional parameters and no output schema, the definition is nearly sufficient, and naming the intended consumer (google_ads_add_audiences) plus the ID return covers the essential chain. The one gap is the no-argument behavior: it is not stated whether omitting 'query' lists all available segments or all account lists.

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 coverage is 100%, so both parameters are already documented, including the example terms for 'query'. The description adds only the 'by name' framing, which the schema's 'Words to search in segment names' already conveys. Baseline 3 is appropriate.

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?

Uses a specific verb and two distinct resources: searching Google's affinity/in-market segments by name, and listing the account's own audience lists (remarketing, customer lists). It also states the downstream use ('Returns IDs for google_ads_add_audiences'), so the agent knows exactly what the tool yields and why.

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 link to google_ads_add_audiences makes the retrieve-then-attach workflow clear, which is the main usage context. It does not state when to use a platform-specific sibling (meta_audiences, tiktok_audiences, ga4_audience) instead, nor does it explain what happens when 'query' is omitted versus supplied.

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