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

The description adds only the phrase 'for this session' beyond what annotations already declare (readOnlyHint=true). It discloses the read-only nature implicitly, consistent with annotations, but does not elaborate on potential errors (e.g., unauthenticated state) or return specifics. Given annotations cover the safety profile, the minimal extra context warrants a middle score.

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?

The description is a single, front-loaded sentence with zero waste. It immediately states the action and the object, leaving no room for verbosity. This is an exemplary concise and structured definition.

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, no-output-schema tool, the description is fully complete. It tells the agent exactly what the tool returns (the authenticated API account) and when it applies (this session). There are no missing details an agent would need to invoke it correctly.

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 has zero parameters, and the schema reflects this with no properties. Per the rubric, a zero-parameter tool receives a baseline of 4 because there are no parameter semantics to clarify. The description's mention of 'authenticated account' adequately orients the user to what is returned, even though no params exist.

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 'Get the authenticated API account for this session' clearly states the specific verb (get) and resource (authenticated API account). It is distinct from all sibling tools, which target external platforms, by focusing on the session's own auth identity. There is no ambiguity about what this tool does.

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 provides clear context: it retrieves the account associated with the current session. While it does not explicitly name alternatives or exclusions, it is unique among siblings (none other deal with auth identity), so the usage context is implicit and sufficient. A score of 4 reflects clear context without explicit when-not guidance, which is acceptable given the tool's uniqueness.

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