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

Annotations already declare readOnlyHint=true, destructiveHint=false and closed-world, so safety is covered. The description adds real behavioral context beyond them: the empty-list semantics ('they aren't in a squad yet') and the ordering dependency on downstream squad tools. It does not describe the shape of a populated result, but with no output schema that gap is minor.

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?

Three short sentences, each earning its place: identity/return value, invocation trigger, empty-state branch. The most important guidance (call first) 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 no-argument, read-only list tool, the definition covers what is returned, when to call it, and what an empty result implies, routing the agent onward. Nothing needed to invoke it correctly is missing.

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?

Zero parameters, so the baseline of 4 applies; there is no parameter surface for the description to illuminate or obscure.

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?

Specific verb+resource ('List the Squadcard squads the user is in') with scope spelled out, plus the key differentiating detail that the result carries the id other squad tools require. An agent can distinguish this from get_squad (needs a squadId) without opening either schema.

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?

Explicit routing: 'Call it first when you don't have a squadId.' It also names the two alternatives for the empty-list branch (create_squad, join_squad), covering both the when-to-use and the fallback path.

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