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

Goes well beyond the destructiveHint/idempotentHint annotations by spelling out what is destroyed (lead deleted), the reversibility window (restorable within 30 days), and the side effects (meeting cancellations with Google guest notification, card refusal). This is exactly the behavioral detail an agent needs before a destructive call.

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 verb+resource, then a single dense sentence listing consequences. It is a run-on but nearly every clause carries an effect the agent must know; only minor tightening is possible.

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 destructive, two-param tool with no output schema, the description covers the destructive footprint and reversibility thoroughly. It omits any mention of permission/authorization requirements or error conditions, but nothing essential for correct invocation 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 the baseline is 3, but the description adds genuine meaning: contact_id blocks 'every address the contact holds' (multi-address semantics) and card_id is optional ('if any') with the block serving as the refusal reason. That clarifies optionality and effect beyond the schema strings.

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?

States a specific verb and resource ('Block a lead's sender') and enumerates the exact cascade: addresses blocked, lead disqualified/deleted, meetings cancelled, card refused. An agent can distinguish it from unblock_a_sender and list_blocked_senders without opening any schema.

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?

Describes the operation's effects but gives no when-to-use guidance, no prerequisites, and never names an alternative (e.g., unblock_a_sender, delete_contact, set_the_lead_status) or the condition that would select this tool over them. Usage must be inferred entirely from the effect list.

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