Get a free validation key

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

Beyond annotations, the description reveals that the key is held in memory for the session, is only needed conditionally, and is subject to specific quotas. This meaningfully supplements the readOnlyHint/idempotentHint flags and gives the agent a clear behavioral model.

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: the core action, the usage condition, and the quota constraints. The quota list is dense but every item is operationally relevant, and the description is front-loaded with the primary purpose.

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 simple one-parameter tool with no output schema, the description covers purpose, when to use it, side effects, and limits. The only minor gap is that it does not explain how validation tools consume the key held in memory, but this is likely implicit in the session context.

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%, and the only parameter 'label' is already documented as 'Name for the key.' The description adds no additional parameter-level meaning, but the baseline of 3 is appropriate because the schema fully covers 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?

The description states a specific action ('Issue a free canlicapital.com validation key'), the resource, and the HTTP endpoint. It also distinguishes this tool from sibling read tools by explicitly noting which tools never need 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?

It gives explicit when-to-use guidance: only before a validation when neither CANLI_KEY nor local mode is set. It also names the read tools that should not use this tool and includes quota limits that affect usage decisions.

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