has_connect_plus

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

Annotations cover only readOnly/openWorld, so the description carries the rest and delivers: it reads from the cached socialProfile endpoint, states that usually no extra request is made, and explains how subscription status is derived. It even discloses downstream error semantics, which is rich context beyond the annotations.

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?

Front-loaded with the plain-language purpose before the implementation detail, and every clause is informative. It is a single dense sentence with heavy parenthetical nesting, which costs some readability, but little could be cut without losing the derivation and error semantics.

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 takes on the burden of explaining the return value, and it does so precisely (true when hasPremiumSocialIcon/userRoles conditions hold). Given zero parameters and existing annotations, nothing an agent needs to invoke and interpret this tool 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-based baseline of 4 applies. The description correctly adds no parameter guidance because there is none to add.

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 precise predicate and its exact computation: true when hasPremiumSocialIcon is true or userRoles holds a ROLE_SP_FEATURE_n entry. It is unmistakably distinct from any sibling, several of which are named as dependencies. An agent knows exactly what this tool answers.

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?

Explicitly names the CONNECT_PLUS_METHODS that require this check and the failure mode (GarminConnectPlusRequiredError instead of a bare 403), giving strong context for when the call matters. It stops short of an imperative 'call this before X', but the conditions that select this tool are clear and nothing is misleading.

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