validate_address

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the description doesn't need to restate safety. It goes beyond annotations by disclosing the tool returns a corrected version plus notes about missing/unconfirmed/inferred items. However, it doesn't mention if authentication or rate limits apply; a 4 is appropriate given annotations cover the core behavioral profile and the description adds meaningful context.

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 concise sentences front-load the key action and return value, then immediately provide usage guidance with an alternative. Every sentence adds value, zero wasted words.

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 only 2 params and an output schema present, the description doesn't need to explain return structure. It covers purpose, when to use, and behavioral output. It doesn't specify parameter formats or required permissions, but for a simple read-only validation tool with few params, this is nearly complete.

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 0%, so the description must compensate. It doesn't explain what address_lines expects (e.g., format, order) or what region_code means (e.g., ISO code). The schema has two parameters but the description provides zero parameter-specific guidance. Baseline is 3 due to low coverage, but the description adds no parameter detail, so 3 is the maximum possible here.

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 states exactly what the tool does: check if a postal address is real and deliverable, and return a corrected, standardized version with notes about missing or inferred information. The verb 'validate' paired with 'address' is specific, and the description clearly distinguishes this tool from siblings like geocode_address.

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 explicitly says when to use this tool ('before relying on an address a user typed') and when not to (use geocode_address when you only need coordinates). This direct guidance with a named alternative clarifies decision-making.

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