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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=true, so the safety profile is covered. The description adds one piece of genuine extra context — the required contract_documents:write scope — but says nothing about partial vs. full update semantics or which fields are mutable, leaving mutation behavior under-explained.

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 short sentences with zero redundancy, and the core action plus the key constraint are front-loaded. Every sentence earns its place.

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 covers the action, the lookup key, and the auth scope, while annotations carry the destructive/idempotent profile and the schema documents all fields. It is nearly complete, with only update semantics (partial vs. full) left unstated.

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 100% across all seven parameters, so the schema already documents each field, including the required id. The description only restates that lookup is 'by ID' and adds no syntax, format, or mutability meaning beyond what the schema provides, so baseline 3 applies.

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 contract document by ID'), which is unambiguous and identifies the entity precisely. It does not, however, differentiate itself from closely related siblings such as update_contract or bulk_update, so an agent gets no routing help beyond the resource name being explicit.

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 phrase 'by ID' implies the ID is required and the scope requirement gives a precondition, which is implied usage guidance. There is no explicit statement of when to use this versus update_contract, bulk_update, or delete_contract_document, so the agent must infer the choice.

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