Get Monarch subscription

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered structurally. The description adds value beyond annotations by disclosing the breadth of data returned (plan, entitlement, trial, payment-source) — exactly the kind of context that helps an agent set expectations for a single request.

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?

A single, well-formed sentence that front-loads the verb and resource, then lists the specific metadata dimensions. Every clause earns its place; there is no filler, boilerplate, or repeated structured information.

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 zero-parameter, read-only getter with an output schema present, the description is complete. It tells the agent what data the call returns, and the annotations + output schema carry the behavioral and return-format burden. Nothing an agent needs to select and call this tool 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?

The tool takes zero parameters, so the schema coverage is 100% with nothing to document. The description correctly adds no parameter syntax. With no parameters, this is the baseline score of 4 — there is nothing more the description could contribute.

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?

The description states a specific verb ('Get') and resource (Monarch subscription) and enumerates the return content — plan, entitlement, trial, and payment-source metadata. This clearly differentiates it from all sibling tools, which cover accounts, transactions, budgets, and cashflow, none of which overlap with subscription data.

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?

The purpose implies the use case — retrieving subscription/plan metadata from Monarch — but the description offers no explicit guidance on when to choose this over alternatives or any conditions/exclusions. With no directly competing sibling (all siblings are in other data domains), the absence of exclusions is minor, but the guidance is still implied rather than stated.

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