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

Annotations already flag destructiveHint=true and idempotentHint=false, but the description adds real value beyond them: the lead enters the loser state, an event is logged for audit, and no notification is sent to the lead. It does not address reversibility or whether re-running on an already-lost lead errors, which matters given idempotentHint=false.

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?

Three compact sentences front-load the state change, then side effects, then options. The trailing endpoint reference is cheap and unambiguous; nothing is wasted.

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 key facts: state change, event logging, no outbound message, and optional comment/category. It omits any mention of the scheduling parameters that exist in the schema and does not say what the call returns, both minor given the fully documented schema and annotations.

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 description coverage is 100%, so the baseline is 3. The description only echoes two of the five parameters (comment, category) and adds a small clarification that the category must already exist; it says nothing about call_back_in or scheduled_for, leaving the agent to rely entirely on schema descriptions.

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 ('Mark a lead as a loser') and immediately disambiguates the term with '(not interested / lost)'. Combined with the sibling name mark_lead_winner, an agent can tell exactly which state transition this performs without opening the 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?

The parenthetical '(not interested / lost)' plus 'nothing is sent to the lead' gives clear context for when this is the right transition rather than a winner/callback mark. It stops short of an explicit exclusion (e.g. use mark_lead_winner instead when the deal closed successfully), so no true when-not guidance.

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