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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds value by revealing the shape of the return payload (subcontractor, amounts, retainage, scope, items) in the absence of an output schema, though it says nothing about error behavior when the id is not found.

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?

A single short sentence that front-loads the resource and lists of return fields without filler. It is efficient, though the missing verb makes it read as a fragment rather than a statement of action.

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 simple single-record read with full annotation coverage and one well-documented parameter, the description is adequate. The main residual gap is that it only gestures at the response contents and says nothing about not-found behavior, which matters since there is no output schema.

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?

There is one parameter with 100% schema description coverage, and the schema already explains where the id comes from. The description adds nothing about the parameter, which is the expected baseline when the schema carries the burden.

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 names the resource (a sub-contract) and enumerates what it contains (subcontractor, amounts, retainage, scope of work, items), which distinguishes it from list_sub_contracts. However it is a noun phrase with no verb ('One sub-contract with...'), so the retrieval action is only implied rather than stated.

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?

No guidance on when to use this versus list_sub_contracts or the create/update siblings. The only routing hint ('sub_contract_id from list_sub_contracts') lives in the schema, not the description, so the description itself offers no usage context or prerequisites.

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