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

With no annotations, the description carries the full burden. It usefully discloses the data granularity ('monthly') and the four metric families returned, but leaves read-only/latency/rate-limit/auth behavior to inference from the verb 'Get'. It adds real content, yet key operational traits are unstated.

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 that states the action and the four outputs with no filler. Every clause earns its place.

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 two-parameter lookup with no output schema, the description helpfully enumerates the returned fields, which is the main completeness gap it needs to fill. It stops short of noting data source, freshness, or market requirements, but the essentials for calling it correctly are present.

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 100%, so both parameters are already documented, including the country default. The description adds only the loose phrase 'for any keyword' and mentions Google Ads CPC (a metric, not a parameter); nothing extra about country_code semantics or how it scopes the volume figures.

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?

Specific verb ('Get') plus a precisely enumerated resource: monthly search volume, Google Ads CPC, competition difficulty, and search intent. No sibling tool covers SEO keyword metrics, so an agent can route here unambiguously from the name and description alone.

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 says nothing about when to use this tool versus alternatives, nor about prerequisites such as needing a specific market or the cost/quota implications of a paid Google Ads data source. 'For any keyword' only implies breadth, which is not real guidance.

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