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

Annotations already mark this readOnlyHint=true and destructiveHint=false, so the description's burden is reduced. It still adds value by confirming 'Changes nothing' and describing the returned shape. It does not mention pagination behavior despite a limit parameter with a maximum, which is the main remaining gap.

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, front-loaded with the action and its return shape, followed by the optional filter and the downstream id usage. Every clause carries information and none is padding.

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 usefully enumerates the returned fields, and it covers the filter parameter. It omits pagination/limit semantics, which matters for an unbounded read on subscriptions, so it is close to but not fully complete.

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 100%, so all three parameters are already documented with defaults and bounds. The description only re-states the code filter and says nothing about limit or business, so it adds no meaning beyond the schema — the correct baseline of 3.

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 clear verb+resource ('List subscriptions') and goes further by enumerating the returned fields (id, plan, status, subscriber), which tells an agent what it will actually get. It does not explicitly distinguish itself from the nearby sibling agenta_subscriptions_credits, so it stops short of a 5.

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 a concrete filter condition ('pass code to see only subscribers who used that discount code') and routes the agent to the follow-up tools that consume an id (cancel, change_plan, credit). It lacks explicit when-not-to-use guidance or a pointer to the related credits/credits-listing sibling, so it is clear but not exhaustive.

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