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

Annotations give readOnlyHint=false, idempotentHint=true, destructiveHint=false, so safety and idempotency are covered structurally. The description adds real behavioral context: this is a partial record that does NOT complete the milestone or release payment, which is exactly the non-obvious trait an agent could misread.

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?

Three short sentences, zero waste, with the core action front-loaded and the disclaimers following immediately.

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?

An output schema exists, so return values needn't be explained, and annotations cover the safety profile. But with 0% param coverage and no hint at the param hierarchy or which identifiers are required, the definition leaves an agent guessing at how to populate the three UUIDs.

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 0% and the description names no parameters at all; the three UUID params (milestoneSetId, milestoneId, criterionId) and their hierarchical relationship are only inferable from the schema's $ref nesting. The description does not compensate for the coverage gap.

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?

Specific verb+resource: 'Record that one saved acceptance criterion was met.' It precisely names the grain (one criterion) and the precondition (must already be saved), distinguishing it from siblings like save_acceptance_criterion and declare_milestone_complete.

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?

States the precondition (criterion must already be saved) and clarifies scope, but never names the alternative tool for the 'next step' it disclaims. An agent knows when it can call this, but not explicitly which sibling to call when the case doesn't fit.

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