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

Goes beyond the annotations by disclosing a failure/lockout threshold ('after five wrong codes the email stops accepting codes') and an operational constraint (must obtain the code from the user rather than guessing). Annotations already cover idempotency and non-destructiveness, and the described behavior is consistent with idempotentHint=true. It doesn't state what a successful confirmation unlocks or whether the code is single-use, which keeps it short of a 5.

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?

Three tight sentences with zero padding; the core action and its required input come first, followed by the handling instruction and then the failure escape hatch. Every clause carries information the agent needs.

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 one-parameter confirmation tool with full annotation coverage, the description supplies action, input source, lockout behavior, and the alternative path. The only gap is the absence of any statement about the result of success (no output schema exists to cover it), which is minor but not fully closed.

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 coverage is 100%, so the format ('Six digits, e.g. 042917') is already supplied structurally, giving a baseline of 3. The description adds genuine meaning beyond the schema by identifying the provenance of the value – it is the code emailed to the owner and is obtained by asking the user – which tells the agent where to source the parameter.

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 and resource ('Confirm the owner's email') plus the artifact required ('the six-digit code SimpleDock emailed them'), so the agent knows exactly what this does. It is clearly distinct from the similarly named sibling resend_verification_email, which it explicitly points to for the alternate path.

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?

Gives explicit when-to-use instruction ('ask the user for the code they received'), an explicit prohibition ('never guess one'), and names the alternative tool and the exact condition that selects it ('after five wrong codes ... use resend_verification_email'). Nothing about routing is left to inference.

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