Update Company Vendor Business Register

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

Beyond annotations (readOnlyHint=false, destructiveHint=false), the description discloses the side effect that changing a verified register's identifier nulls verification_status and verified_at. It also explains that omitted fields retain values and describes error statuses (401/403/404) and return value, providing rich behavioral 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?

Eight sentences, each carrying meaningful information. It is front-loaded with the primary purpose and logically organizes preconditions, side effects, usage, error handling, and endpoint details. The final 'Required parameters' line is slightly redundant with schema but not harmful.

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, the description fully covers the operation: it states the return value ('Returns the modified company vendor business register'), error semantics, side effects, id resolution requirement, and the API endpoint. No obvious gaps for an agent to invoke it 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 baseline is 3. The description adds the crucial note that fields should be passed as top-level arguments even though the API nests them under 'business_register,' and clarifies that id must identify an existing parent record resolved via a list tool. This exceeds schema-only information.

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 opens with 'Update an existing Business Register associated with a specified Vendor' — a specific verb and resource. It explicitly states the register 'must already exist,' distinguishing it from the sibling create_company_vendor_business_register and other update tools.

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?

It clearly states the precondition ('Register must already exist') and instructs to resolve id with the matching list tool first. It also describes partial-update semantics. However, it doesn't explicitly name a sibling list tool or state 'use create tool for new registers,' so exclusions are implied rather than explicit.

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