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

With annotations already declaring readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false, the description adds real value beyond them: sender identity is auto-filled, the recipient's business email stays private, the owner is notified in their inbox, and a confirmation is mandatory. It could still say more about delivery/rate behavior, so a 4 rather than 5.

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?

Two tight sentences: the first front-loads purpose and recipient scope, the second bundles the key behavioral constraints (auto identity, privacy, notification, confirmation). No filler.

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 6-parameter mutation tool with no output schema, the description covers the critical flow (confirmation gating, privacy, notification) and the recipient scope. The token mechanics and return shape are left to the schema, which is acceptable, but a bit more on what a successful start produces would round it out.

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 67%, and the description adds only the note that the signed-in member email is used automatically (explaining why no email parameter exists). It says nothing about the message, phone, or looking_for parameters and does not compensate for the two undocumented schema fields. Baseline 3 is appropriate.

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 names a specific verb and resource: 'Start a new FirmLedger Leads conversation with another approved, claimed business.' This is clearly distinguishable from siblings like reply_to_lead (continuing an existing thread) and list_leads/get_lead (reads), though it never names those siblings explicitly.

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?

It states a concrete precondition ('another approved, claimed business') and a workflow requirement ('Requires the user's confirmation of the exact inquiry'), which tells the agent not to fire blindly. It stops short of explicitly naming alternatives or listing when-not-to-use cases, so it falls below the 5-level.

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