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

Annotations already convey read-only, idempotent, non-destructive behavior. The description adds value by disclosing the OAuth authorization requirement and the fact that no arguments are needed, which are not expressed in the annotations or schema.

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 with no filler. The purpose is front-loaded, and each sentence earns its place: one for what the tool does and one for the key usage/auth context.

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 tool with robust annotations, a fully self-documenting schema, and no required parameters, this description covers everything needed to call it correctly. It adds the critical OAuth prerequisite and makes the no-argument usage explicit.

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% and the schema fully describes chain and api_key, including the default behavior and OAuth exemption. The description's 'works with no arguments' restates the zero-required-parameter schema but doesn't add meaningful parameter semantics beyond it.

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 names a specific verb ('Check') and resource ('a linked wallet's stablecoin balances and remaining agent spending allowance'), making the purpose clear. It doesn't explicitly contrast itself with siblings like transaction_history, but those siblings don't handle balance queries, so the differentiation is implicit.

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 description gives clear usage context: it works with no arguments and requires the connector to be authorized via OAuth. It doesn't explicitly discuss alternatives or exclusions, but no sibling tool closely overlaps in purpose, so the guidance is reasonable.

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