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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds useful behavioral detail beyond annotations: milestones are returned ordered by target amount and include both target amount and reached status. This is meaningful for an agent predicting the tool's output and behavior.

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 three short, purposeful sections with no filler. The main verb-resource statement is front-loaded, followed by a minimal parameter description and a concise return summary. Every sentence earns its place.

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 one-parameter, read-only, non-destructive list operation with no output schema, the description is complete: it states the operation scope, required input, ordering, and returned fields. No pagination, error, or mutation details are necessary. The absence of an output schema is mitigated by the explicit return description.

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?

The schema only provides an integer type and title 'Goal Id', with 0% schema description coverage. The description compensates by explaining that goal_id is 'The goal whose milestones to list,' clarifying the parent-entity relationship. For a single, simple integer parameter, this is sufficient semantic guidance.

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 and resource: 'List all milestones for a goal.' It clearly distinguishes this read-only listing tool from siblings like create_milestone, update_milestone, delete_milestone, list_goals, and list_goal_plans. The scope ('for a goal') and ordering detail ('by target amount') make the tool's purpose unmistakable.

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 intended use is implied by the phrase 'for a goal' and the required goal_id parameter, but no explicit when-to-use guidance or alternatives are mentioned. It does not exclude other list tools or explain when this tool is preferable to related milestone or goal retrieval tools. The guidance is serviceable but relies on inference.

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