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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds useful context beyond annotations: it explains that all writes are stamped with createdBy/updatedBy = key name, helping the agent understand why verifying the key first matters.

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 two short, information-dense sentences. The most important behavioral cues—return value and 'call this first'—are front-loaded, and every clause adds value.

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 identity/auth check tool, the description is complete: it names the return payload, explains the non-destructive nature, and gives clear invocation guidance. No output schema is necessary given the simple return value described.

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, so there is no parameter meaning to clarify. The description appropriately focuses on return value and usage context instead, making the schema's empty properties object fully sufficient.

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 exactly what the tool does: 'Returns key name + workspace.' It is clearly distinguished from all sibling tools, which are CRUD/data operations rather than an authentication identity check. The title 'Verify your API key' reinforces the purpose.

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 explicitly says 'Call this first,' giving a direct usage directive. It also labels itself as a non-destructive auth check, which makes it obvious that this is a safe preliminary step before mutation tools. Given the sibling list is all write/read operations with no other auth tool, no alternative comparison is needed.

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