Add negative keywords

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

The readOnlyHint=false annotation already tells the agent this is a mutation, so the description adds little. It does specify the platform is Google, but it omits which campaign is affected, how keywords are supplied, reversibility, and permission requirements — significant gaps for a write operation.

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 front-loaded sentence with no filler, which is good, but it is under-specified rather than concise — the brevity comes at the cost of telling the agent what the tool actually operates on.

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 mutation tool with no output schema, no usable parameter definitions, and only a readOnlyHint, the description carries most of the burden and carries it poorly. It lacks the campaign identifier, keyword input format, and any result expectations an agent needs to call this correctly.

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?

Parameter count is zero, which normally earns a baseline 4, but the schema is an open bag (additionalProperties: true) with no declared properties or descriptions — the agent must guess the payload shape. The description does nothing to clarify what keys (keywords, campaign id) should be passed, so it cannot claim the clean zero-param baseline.

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 conveys the outcome (prevent a Google campaign from showing on unwanted searches) but never names the mechanism — negative keywords — or states a verb+resource pairing like 'add negative keywords to a campaign.' An agent can infer the intent from the tool name, but the description itself is oblique.

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?

No guidance on when to use this versus siblings such as update_keywords, research_keywords, or create_ad_group, and no stated preconditions (campaign must exist, account must be connected). The agent gets no routing signal at all.

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