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

With readOnlyHint=true annotation, the safety profile is clear. The description adds value by disclosing the exact fields returned (goal, weeks, difficulty, systems, tasks with their attributes), which is useful behavioral context beyond the annotation.

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, compact sentence that thoroughly captures the tool's output in a structured list. Every word earns its place, and the key phrase 'ONE milestone' is front-loaded.

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 simple read-only get tool with no output schema, the description sufficiently outlines the response contents. It does not describe error handling or ambiguity cases, but these are less critical given the schema's optional parameters and the tool's simplicity.

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 67%, and the schema already explains id as 'Preferred' and name as 'If no id'. The description does not add extra semantic meaning for parameters, including project_id which lacks a schema description. Baseline 3 is appropriate as schema does most of the work.

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 clearly indicates the tool retrieves a single milestone ('ONE milestone') and enumerates its contents (goal, weeks, difficulty, systems, tasks). This distinguishes it from list_milestones, though the verb 'get' is only implied by the tool name.

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 implies use for a single milestone rather than a list, but does not explicitly state when to use it over siblings or mention alternatives. There is no guidance on parameter selection or prerequisites beyond the schema hints.

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