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

Annotations only say this is a non-readonly, non-destructive, non-idempotent write; the description goes far beyond that by disclosing the temporal blast radius, that historical documents are immutable, and that each change is logged as a record. This is exactly the kind of consequence disclosure a mutation tool needs.

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 the action and effect scope, and the trailing 'Effects:' line is a useful summary. Slightly repetitive — the 'future documents' idea is stated twice — but nothing 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?

For a two-parameter mutation with annotations and full schema coverage, the description covers the key behavioral consequence (immutability of already-raised documents) and the audit nature of the act. It does not mention permissions or what the call returns, but no output schema exists and those are minor omissions.

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% and the schema already documents item_id and the cents-based unit_price, so the description adds no parameter-level meaning. Baseline 3 is appropriate when the schema does the work.

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 ('Change an item's list price') and immediately qualifies the scope (future documents only). It is clearly distinct from core_create_item or inventory cost tools, though it never names a sibling to route against.

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 clear context for when the change applies: documents raised from now on, with quotes already accepted and issued invoices unaffected (INV-19). It explains the rationale ('logged act and not a field edit') but offers no explicit exclusions or named alternatives for adjacent operations.

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