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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds nothing beyond that – no error/not-found behavior, no note on what is returned – so it neither contradicts nor enriches the annotations.

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?

One short sentence, front-loaded with the verb and resource, with zero filler. Every word 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 trivial single-entity lookup with rich annotations and a fully documented parameter, the description is nearly sufficient. The remaining gap is that no output schema exists, so the agent gets no signal about the returned milestone shape; a brief hint would close it.

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?

There is a single parameter with 100% schema description coverage ('Project milestone ID', uuid format), so the schema fully documents it. The description only restates that the lookup is by ID and adds no format or scoping detail beyond the schema, which is the baseline-3 case.

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?

States a specific verb ('Get') and resource ('project milestone') plus the lookup key ('by ID'), which cleanly separates it from bulk_create and from list_project_milestones. It stops short of naming the sibling list tool explicitly, so the differentiation is implied rather than declared.

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: 'by ID' tells the agent this is a point lookup rather than a listing, but there is no explicit when-to-use statement, no guidance on preferring list_project_milestones for discovery, and no note about behavior on a missing ID. Adequate but with clear gaps.

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