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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine behavior context by characterizing the return payload as a shallow, high-volume list view, which tells the agent not to expect rich per-lead data. It doesn't mention pagination defaults or result ordering, which is the remaining gap.

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?

Four tight sentences: scope first, payload shape second, sibling routing third, filter semantics last. No filler, no repetition of schema or annotation content.

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?

With no output schema, the description carries the burden of describing results and does so at the right altitude ('many leads, a few fields each'). All 7 params are documented in-schema and the key filter is elaborated. Missing only ordering/default-window behavior, a minor gap for a list tool with zero required params.

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 baseline is 3. The description earns above baseline by explaining the `status` filter operationally - translating enum values into the human questions they answer - which is meaning the schema's one-line 'Filter by pipeline status' does not provide.

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 resource (prospects/leads) with scope variants (a campaign, or the whole account) and the payload shape ('many leads, a few fields each'). It then explicitly separates itself from three siblings by name, so an agent can pick it 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?

Gives explicit when-not-to-use routing: use `lead_get` for one person's full record, `lead_flow_state` for sequence position, `lead_export` for a spreadsheet. It also gives concrete when-to-use examples for the `status` filter ('who replied this week' → REPLIED, 'accepted but never answered' → CONNECTED).

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