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

Annotations already declare destructiveHint=true and openWorldHint=true, so the bar is lower; the description adds real value by explaining the blast radius ('appended to every final URL the platform serves') and that clearing is supported. It stops short of saying the existing suffix is overwritten wholesale or what validation errors occur, but the mutation scope is disclosed.

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 sentences, front-loaded with the verb and resource, no filler. The second sentence is slightly malformed as a fragment ('The suffix is appended..., typically UTM parameters...'), which costs a point but not readability.

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?

No output schema, but the tool is a simple three-parameter mutation with fully documented parameters and a disclosed effect on served URLs. Missing only edge details such as overwrite semantics for an existing suffix and failure modes, which are minor for this operation.

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%, with format, allowed characters, max length, empty-string-clears behavior, and the channel enum all documented in the schema. The description's only addition is that the suffix is 'typically UTM parameters for tracking (utm_source, utm_medium, ...)', which is marginal but does illustrate intent.

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 (Set or clear) plus a precise resource (Final URL Suffix on a wizard campaign's search channel), and scopes the valid channels to Google Ads or Microsoft Ads. It is distinguishable from siblings like set_campaign_utms and set_search_channel_locations, though it never names an alternative explicitly.

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 phrase 'Set or clear' signals both operating modes, which is useful. However, it gives no guidance on when to use this versus set_campaign_utms or set_search_channel_locations, nor any prerequisites (e.g., campaign must be a wizard campaign, channel must be connected) beyond what the schema enum implies.

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