Get the current user

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

The annotations already declare readOnlyHint true, so the safety profile is clear. The description adds significant behavioral context by detailing the two projection modes and their impact on response size ('embeds every single one of them' for full, which suggests it can be large). This goes beyond annotations and 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 zero waste. The first sentence clearly states the core purpose, and the second adds the crucial distinction between projections. Every word earns its place.

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?

Given the low complexity (1 optional parameter, no output schema, read-only) and full schema coverage, the description is complete. It explains the parameter behavior and the response implications. No output schema is needed because the description covers the return shape sufficiently for agent use.

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 description coverage is 100%, so baseline is 3. The description adds meaning beyond the enum by explaining the practical trade-off (counts vs full embedding), which helps the agent decide which value to use. It also notes that 'compact' is the default, which is not in the enum description.

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 specifies both the verb ('Returns') and the resource ('the Audiobookshelf user the API key acts on behalf of'), clearly distinguishing it from siblings like get_series or list_libraries. It also clarifies the key difference between the two projections, which is unique to this tool.

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 implicitly indicates when to use the 'compact' vs 'full' projection based on whether one wants counts or full data. However, it does not explicitly state when not to use this tool or compare it to alternatives (e.g., get_server_status). It lacks 'when-not' guidance but is clear on context.

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