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

Annotations already declare destructiveHint=true and idempotentHint=false, so the agent knows this is a risky, non-idempotent mutation. The description adds almost nothing beyond that: it never says whether omitted fields are left untouched or cleared, whether updates can be reverted, or that setting status='archived' is the archival path. For a destructive 25-field mutation, that omission is significant.

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 short sentences, front-loaded with the action and the required identifier. No filler, though the cross-reference to create_customer is an indirection rather than genuine compression.

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 25 parameters, 0% schema coverage, no output schema, and destructiveHint=true, the description should cover partial-update semantics and the effect of archiving; it covers neither. The create_customer cross-reference is the only substantive help, and it is insufficient for an agent to call this safely.

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% across 25 parameters, so the description carries the full burden and mostly punts: 'Same fields as create_customer' forces the agent to open another tool's schema to learn what is editable. Only 'status (active or archived)' is explained, and that merely restates the enum already in the schema.

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 ('Update a customer') and scopes it to 'this organization', which lets an agent separate it from create_customer, get_customer, and delete_customer in the sibling list. It stops short of naming any sibling explicitly, so it is clear but not differentiated by prose.

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?

There is no statement of when to use this tool versus alternatives such as update_item, update_supplier, or upload_customer_logo, and no prerequisites (permissions, whether the customer must already exist). The only usage-adjacent fact is that customer_id is required, which the schema already enforces via the required array.

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