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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful temporal scope ('current') and enumerates the placement categories, but it does not disclose behavior when campaign_id is omitted, nor the output format or units.

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?

The description is one compact, front-loaded sentence with no filler. The parenthetical list of placement categories efficiently adds detail without bloating the text.

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?

This is a simple read-only lookup with two optional parameters and no output schema, so the description is fairly adequate. However, it does not state the output shape, units of modifiers, or the behavior when only profile_id is supplied, leaving some ambiguity for an agent.

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 only 50%: profile_id is documented, but campaign_id has no schema description. The description's phrase 'per campaign' gives some meaning to campaign_id, but it does not explain whether it is optional, whether omitting it returns all campaigns, or what format is expected.

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?

The description names a specific resource (placement bid modifiers), a clear scope (per campaign), and specific placement categories (top of search, product pages, rest of search). It lacks an explicit verb like 'get' or 'list,' but 'current' strongly implies read-only retrieval and the title reinforces the same meaning.

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 description implies the tool should be used when you need current placement bid modifiers for a campaign, but it gives no explicit when-to-use guidance or alternatives. With siblings like ppc_placements and ppc_campaign_details nearby, some routing direction would be valuable, but the core use case is inferable.

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