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

The description goes well beyond the annotations by explaining the over-tolerance check, refusal unless damaged, automatic shortage calculation with flooring at zero, discrepancy display, and partial-delivery behavior. It also states 'full CRUD,' clarifying the mutation profile. This adds substantial behavioral context that annotations alone do not provide.

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?

The description is moderately sized and front-loaded with the core action. Every sentence contributes useful behavior or constraints, though 'Free tier, full CRUD' is somewhat redundant with annotations and could be trimmed without losing essential invocation guidance.

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 5-parameter mutation tool with no output schema, the description covers the essential validation rules, partial-delivery behavior, and automatic shortage calculation. The main gap is that it does not describe the return value or confirmation response, which would help an agent verify the result of the call.

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 the schema already documents every parameter. The description adds meaningful semantics on top: received is checked against ordered quantity and over tolerance, shortage is auto-calculated as ordered minus received floored at zero, and each line gets one cell for received and/or damaged units. This clarifies the relationship between parameters beyond raw field descriptions.

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 a specific verb and resource: 'Create a goods-receipt note (GRN) against an open purchase order.' It clearly distinguishes this from sibling tools by emphasizing creation of a GRN for receiving goods, not closing, listing, or adding lines to an existing GRN.

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 gives clear context for when to use the tool: receiving whole units against an open PO, with partial deliveries explicitly supported ('raise several GRNs against the same PO'). It does not explicitly name sibling alternatives or state when not to use it, but the usage context is unambiguous.

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