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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds real value beyond that by disclosing the exclusions — API keys, payment profile, and third-party connection secrets are never returned — which prevents an agent from calling it expecting secret material, plus the underlying endpoint for traceability.

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, front-loaded with what is returned, followed by the security boundary and the endpoint. No filler, and the most decision-relevant constraint (secrets excluded) arrives early.

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 carries the burden of describing return values — and it does so by enumerating the returned fields and the excluded ones. Only the exact shapes of nested items (billing vs. business address, app details) are left unspecified, a minor gap for a zero-parameter read.

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 baseline is 4; there is nothing to disambiguate. The description correctly conveys that no identifiers are needed because the account is resolved from the API keys themselves.

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 specific verb (get) and resource (the FinerWorks account tied to the API keys) and enumerates exactly which attributes are returned: username, email, addresses, credits, shipping preferences, app details. That field-level enumeration makes it unambiguous against siblings like get_order or get_product_details.

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?

Usage is only implied: an agent infers it should call this when it needs account/credential context rather than order or product data. The endpoint path 'GET /v3/test_my_credentials' hints at a credential-validation use case, but the description never explicitly says when to prefer this over alternatives or what prerequisites exist.

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