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

Beyond the destructiveHint=true annotation, the description discloses a concrete side effect the annotations cannot express: completing a phase also completes its child tasks. It also flags that MCP approval requirements are org-configurable while business workflow approvals always apply, which is useful gating context for a mutation.

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 action and scope are front-loaded in the first sentence, and each following sentence adds new information (column types, cascade, approvals). The phrase 'through the existing screen service' is an internal implementation detail that adds little for an agent, a minor bit of waste.

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 destructive, non-idempotent mutation with a nested data object, the description covers the side-effect risk, the column ambiguity, and approval gating, and an output schema exists so return values need not be described. Only the status enum semantics remain unexplained.

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 0%, so the description must carry the load. It does explain the updatable data fields (status, target date, actual date) and the dual meaning of columnId, but it adds nothing about the status enum values, what null dates mean, or that status is the only required field inside data.

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 first sentence states a specific verb ('Set') and concrete resources ('a site's milestone status, target date or actual date'), so the operation is unambiguous. The second sentence clarifies that the column may be either a milestone column or a template phase task, which separates it from the plain update_milestone/update_task style siblings without naming them.

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 real preconditions: completing a phase cascades to child tasks ('review that consequence') and business workflow approvals always apply. However, it never says when to reach for this tool rather than update_milestone, update_milestone_column or update_project_task, so the agent must infer the routing itself.

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