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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds a partial view of what the result contains (counts by status, time spent), but does not describe aggregation scope, whether counts are per-project or global, or pagination/limits.

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?

Two compact sentences, front-loaded with the purpose and followed by a docs link. Nothing is wasted, though the trailing URL adds little for an agent that already has the schema.

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?

There is no output schema, so the description should carry more of the return-value burden. It gestures at the return shape ('counts by status, time spent, etc.') but leaves the 'etc.' vague and never clarifies scope (global vs per-project) or result size.

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?

Only one optional parameter exists and its schema description ('Get stats for specific project only') is fully covered at 100%. The description adds nothing about projectId or its default behavior when omitted (presumably all projects), so baseline 3 applies.

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 and resource ('Get statistics about user missions') and names the kind of data returned (counts by status, time spent). It implicitly distinguishes itself from siblings like getMissionDetailsTool and listUserMissionsTool, but never explicitly states the difference.

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?

There is no when-to-use guidance and no mention of alternatives such as getProjectStatsTool, getMissionDetailsTool, or listUserMissionsTool, which are the closest siblings. The agent must infer that this tool is for aggregate stats rather than listing or detail retrieval.

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