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

Despite annotations showing readOnlyHint=false, the description explicitly states 'Nothing is written,' which is valuable behavioral disclosure beyond the structured metadata. It also describes what gets computed and what report sections will appear, giving an agent a faithful model of the operation.

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 a single dense sentence that front-loads the core action and expected output categories, followed by a one-sentence safety note. Every word contributes meaning and there is no padding.

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?

The description explains the scope, the output categories, and the side-effect profile, and the input schema covers the only parameter. With no output schema, it would be even stronger if it described the exact return format, but the listed categories give an agent enough context to invoke it correctly.

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% and the single boolean parameter includeOnlyDiscrepancies is already clearly described in the schema. The tool description itself adds no extra parameter detail, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Reconcile') with a clear resource scope ('every purchase order against every GRN') and enumerates the report's categories, so an agent can distinguish this from sibling tools like grn_list or grn_discrepancy. It is concrete and informative rather than a restatement of the title.

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 description makes clear this is a read-only reconciliation/status tool that compares POs and GRNs, which gives strong context for when to invoke it. It does not explicitly name alternatives or exclusions, but the broad scope and report categories make the intended use clear.

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