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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so the safety profile is fully covered. The description adds one useful behavioral detail — that only *active* subscriptions are returned — but says nothing about scoping when tenant_id is supplied or omitted. Adequate but thin against an otherwise rich annotation set.

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 sentences, zero filler, with the purpose stated first and the usage cue second. Nothing could be removed without losing meaning.

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 read-only list tool with an output schema (so return values need no explanation) and only two parameters, the description covers enough to call it correctly. The remaining gaps — tenant_id override behavior and result limits/pagination — are minor.

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 0%, so the description carries the burden for both parameters. 'Caller's tenant's' implies tenant_id defaults to the caller's own tenant, which is useful, but neither the tenant_id override nor the authorization requirement is explained. Partial compensation only.

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?

'Return the caller's tenant's active service subscriptions' names a specific verb, resource, and scope, and the follow-up sentence implicitly separates it from the sibling add_tenant_service. An agent can tell what it returns and why without opening the 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?

'Call this before offering to add a service, to check what is already subscribed' gives explicit sequencing guidance and a concrete trigger condition. It stops short of naming the alternative tool or stating exclusions, but the when-to-use is unambiguous.

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