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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower. The description adds genuine workflow behavior: that output feeds a missionId into createTaskTool and that tasks require a mission-in-progress. It does not describe pagination or return shape, but that is a minor gap given 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?

Front-loads the purpose, then the workflow reason, then the alternative, in three tight sentences. The docs link is the only optional element and 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?

With no output schema, the description still conveys that the result is a set of missions from which a missionId is selected, which is enough to use it correctly. It stops short of naming return fields, but the workflow framing compensates well.

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 100%, so both parameters are already documented, establishing a baseline of 3. The description clarifies that userId is 'the assignee (a person)', which reinforces but does not extend the schema's own description, and adds no format or constraint details.

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 ('List a project member's in-progress missions') with the scoping qualifier 'in-progress' that narrows it meaningfully. It does not explicitly contrast with the close sibling listUserMissionsTool, so it falls short of full sibling differentiation.

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?

Gives explicit when-to-use ('call this after choosing the assignee... to pick the missionId to pass to createTaskTool') and an explicit when-not with an alternative ('If no mission in progress covers the work... prepare a mission with prepareMissionTool instead'). Both the trigger condition and the fallback sibling are named.

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