Validate Bls Key

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

Although annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, the description adds a critical behavioral nuance: a mistyped key does not raise an error but silently drops to the unregistered 25/day limit. This warning goes beyond simple safety metadata and informs the agent of a failure mode that would otherwise be invisible until days later.

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 compact, front-loaded with the core purpose in the first sentence, and the second paragraph adds essential context without repetition. Every sentence earns its place, and there is no padding or redundancy.

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 tool with one optional parameter and no output schema, the description is complete. It covers what the tool does, why it exists, when to run it, and a critical pitfall. No further information is needed for an agent to use it 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 coverage is 100%: the key parameter is fully described in the input schema, including the omission behavior. The description reinforces the context (testing after setting BLS_API_KEY) but does not add new semantic details about the parameter itself beyond what the schema provides. Baseline 3 is appropriate.

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 clearly states the tool's purpose: 'Test a BLS registration key against the live API and report which tier it unlocks.' This uses a specific verb, resource, and outcome. It is distinct from sibling tools like check_connection or get_account_info, which serve broader or different functions.

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 provides explicit usage context: 'Run this once after setting BLS_API_KEY.' It also explains why this is necessary—a mistyped key silently downgrades to the unregistered limit—giving the agent a clear decision rule. It doesn't explicitly name alternatives, but the context is sufficient for a single-purpose validation tool.

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