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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates a read-only 'check' but does not mention potential side effects (e.g., network calls for website reachability), authentication requirements, or error behavior if the lead does not exist. This lack of transparency could surprise the agent.

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 extremely concise with a single purpose sentence and a well-formatted Args block. Every word earns its place, and no fluff is present. The structure is clean and easy to parse.

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?

Although the tool is simple with one parameter and no output schema, the description does not explain what the check returns, how results are formatted, or what happens if the lead is invalid. An agent invoking this tool would lack expectations about the response, making the description incomplete for real-world use.

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 schema only defines lead_id as a string with no description, so the description adds crucial meaning by specifying it is a 'UUID of the lead to validate.' This gives the agent format and context beyond the bare schema, fully covering the single 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 clearly states the tool's purpose: 'Check the freshness and website reachability of a specific lead.' The verb 'check' and the resource 'specific lead' make the action explicit, and the two aspects (freshness, reachability) define its scope. This distinguishes it from siblings like search_leads, which is for finding leads, and get_usage, which likely returns usage data.

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?

There is no guidance on when to use this tool versus alternatives. It does not specify scenarios, prerequisites, or exclusions. The description only states what the tool does, leaving the agent to infer when it should be chosen over search_leads or get_usage.

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