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

Annotations already declare destructiveHint=true and idempotentHint=true, so safety is covered. The description adds genuine non-obvious behavior: leads that finished their sequence are not deleted but reported in errors, and it caps ids at 1000. It does not mention permission requirements or confirmation flow.

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?

A single dense sentence that front-loads the verb and scopes the selector constraint before the edge-case caveat. Every clause carries information; nothing is redundant.

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 mutation with no output schema, the description covers the selection modes and the notable error-reporting behavior. It stops short of describing reversibility or required permissions, leaving a minor gap for a destructive operation.

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 only 50%, so the description meaningfully compensates by spelling out the mutual exclusivity of ids/filter/all, the 1000-item cap, and the requirement that filter carry at least one non-empty field. This is real added meaning beyond the raw schema for the nested filter object.

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 (Delete) and resource (leads) with scope (from a campaign), which cleanly distinguishes it from the sibling delete_campaign that removes the campaign itself. An agent can tell immediately that this operates on the lead set inside a campaign.

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?

Gives explicit selection semantics — EXACTLY ONE of ids, filter, or all — which is strong operational guidance on how to invoke it. It does not, however, state when to prefer this over alternatives like bulk_update_leads or delete_campaign, so exclusions are absent.

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