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

Annotations cover write/destructive/idempotency, and the description adds real context beyond them: the token cost ratio (one token per five businesses), that it does not enroll the business, that email verification is included free, and that it runs asynchronously returning a job id. The three-state field contract is a useful honesty guarantee. It stops short of saying what re-enrichment overwrites when force is set.

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?

Front-loaded with the core action and outcome, then cost, alternative, and async flow. The long middle enumeration of 50+ fields is informative but the longest sentence in the whole definition and could be trimmed without loss.

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?

No output schema exists, but the description compensates by explaining the return (a job id, polled via get_job_status) and the field-value contract. For a downstream write operation with rich annotations, nothing an agent needs to invoke it correctly is missing.

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 both parameters are already documented in the schema itself (force and result_ids both have descriptions). The description adds no syntax or semantics beyond that, which is the expected baseline when the schema carries the load.

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?

Specific verb+resource ('Fetch each lead's website and extract 50+ fields') with a concrete enumeration of what it extracts. It also explicitly distinguishes itself from enroll_leads and verify_emails, so an agent can route correctly without opening schemas.

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?

Names the alternative and the condition that selects it: 'To keep businesses current, use enroll_leads instead.' It also states the follow-up flow ('returns a job id, poll it with get_job_status') and the cost model, leaving nothing to inference.

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