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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description goes further by setting output expectations — 'working estimates (not a quote)' plus licence pricing and 'factors that move the number'. That framing of precision and authority is real value beyond the structured fields, though it does not say how the range is derived or whether results are deterministic.

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 front-loaded sentence that moves from action to inputs to return content with no filler. Every clause carries information the agent needs and nothing is repeated from the schema.

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 read-only, five-parameter estimation tool with a fully documented schema and no output schema, the description is nearly complete: it covers scope, inputs, and the nature of the returned estimate. The remaining gap is that it does not describe the shape of the response (range format, whether breakdowns are itemised) despite having no output schema to carry that.

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 all five parameters, including the from_system enumeration and the manufacturing Essentials-vs-Premium rule, are already documented in the schema. The description only echoes from_system, users and region, and says nothing about entities or manufacturing, so it adds no meaning over the schema — baseline 3.

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 a specific verb (estimate) and resource (cost range and timeline of migrating to Dynamics 365 Business Central) and lists the driving inputs. That clearly separates it from health/compliance siblings, but it never acknowledges the nearest conceptual neighbour, estimate_bridge_to_cloud_savings, leaving the agent to infer the split from the name alone.

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?

Usage is only implied: 'given the current system, number of users and region' hints at the pre-sales scoping scenario but states no when-to-use trigger, no prerequisites, and no explicit alternative to pick instead. An agent must infer the situation from the parameter list rather than being told.

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