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

Annotations already cover readOnly and openWorld safety. The description adds genuine value beyond them by disclosing the credit cost ('1 SERP credit per successful search', implying failed searches do not bill) and the pagination constraint. It omits rate limits and error behavior, but with annotations present the bar is lower.

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?

Three front-loaded sentences that are tight and useful. The final pagination sentence is mildly redundant with the schema but is short and scenario-relevant, so little is wasted.

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 no output schema, the description compensates by naming the returned fields and format (JSON). Combined with the cost disclosure, use cases, and pagination rule, an agent has everything needed 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?

Schema coverage is 100% — every parameter carries its own description with ranges, defaults, and enum values. The description's pagination note ('start must be a multiple of 10') merely restates the schema's multipleOf constraint, so it adds no meaning beyond structured data. Baseline 3 applies.

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 and resource ('Run a Google search') and enumerates the returned fields (title, URL, snippet, position) as JSON. This is clearly distinguishable from the unrelated sibling tools (email, phone, blacklist, social checks).

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?

Gives explicit use cases — rank tracking, competitor research, finding sources on a topic. It does not name an alternative tool or state when not to use it, but no sibling overlaps this capability, so the guidance is contextually adequate.

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