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

The description warns 'The key is returned once and cannot be retrieved later - report it to the operator.', which is a critical behavioral trait not captured by annotations (readOnlyHint=false, destructiveHint=false). This adds significant value beyond 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?

Three sentences: first states purpose, second gives usage context, third warns about key non-retrievability. Extremely efficient with no redundant words.

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 tool's simplicity (3 params, 1 required, no output schema), the description covers purpose, when to use, behavioral warning, and return behavior. It is fully complete for an agent to select and invoke 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?

Schema description coverage is 100%, so the baseline is 3. The description does not add additional parameter semantics beyond what the schema already provides. The parameters (name, agentId, contactEmail) are adequately described in the schema.

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 states 'Issue this agent its own ZeroDust API key for higher rate limits, with no human signup step.', which clearly identifies the action (Issue) and resource (API key). It distinguishes itself from sibling tools that use the API without needing a key.

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 says when to use: 'only call this when rate limits are being hit, or when setting up an unattended agent that will run repeatedly.' Also clarifies that other tools work without a key, providing clear when-not-to-use guidance.

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