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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, and the description reinforces this ('changes nothing') while adding genuinely new behavioral context: what the response contains (valid flag, missing documents/fields, structural mismatches), the next_step semantics, and the caveat that City/Area-level city matching is only checked at verification time. That caveat is non-obvious and cannot be derived from the schema.

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?

Front-loaded with purpose and the read-only framing, then progressively adds resolution mechanics and return semantics. It is dense and long for one paragraph, but nearly every clause carries information; a small amount of restructuring into sentences would improve scannability.

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?

No output schema exists, so the description carries the return-value burden — and it does, describing the valid flag, what is missing, and the next_step field. Combined with the resolution rules and the City/Area caveat, an agent has everything needed to invoke and interpret this tool 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%, so the schema documents all parameters and the baseline is 3. The description adds resolution logic beyond the schema: that requirement_id or country_iso (+ did_group_type) resolve the requirement, and that requirement_type selects the rule set ('regulation' mirrors panel validation, 'emergency' mirrors E911). Useful added meaning over the field descriptions.

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 — 'Check whether an existing address (and its identity) satisfies a regulation or emergency requirement' — and immediately distinguishes it from the create_* siblings by framing it as a pre-flight. An agent can tell exactly what this does without opening the schema.

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?

Explicitly says to use it BEFORE creating a verification, and routes to alternatives by outcome: create_address_verification when everything is in place, create_regulation_upload_link when documents must be collected, update_identity for missing fields. This is clear when-to-use and what-to-do-next guidance.

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