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

Annotations only supply idempotentHint/destructiveHint/openWorldHint booleans, while the description discloses the concrete side effects: timestamp assignment, category mutation, and an outbound LeadCategoryUpdate webhook. It also details the idempotency semantics that annotations merely flag — repeated calls keep the original timestamp and fire no second webhook.

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 dense sentences, front-loaded with the core action and effects before the routing rationale and idempotency caveat. No filler or repetition of the tool title.

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 one-parameter mutation with no output schema, the description covers effects, idempotency, webhook behavior, and where the result surfaces in reporting. An agent has everything needed to call it correctly and predict its consequences.

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% and the single 'id' parameter is already documented in the schema as the numeric lead ID. The description only refers to 'this lead' generically, adding no format, constraint, or lookup guidance beyond the structured field, so the baseline 3 applies.

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 ('Records that a meeting was actually booked with this lead') and enumerates the concrete effects (sets meetingBookedAt, sets category to meeting_booked, fires LeadCategoryUpdate webhook). It is clearly separable from siblings like update_lead or update_lead_category, which could otherwise be confused with this state transition.

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 a clear condition for use and a strong rationale: Emailchaser never infers meetings from reply text or calendars, so this explicit mark is the only way a meeting counts. It also names the downstream consumers (get_campaign_stats totals.meetings, get_outcomes_report). It stops short of explicitly naming the sibling alternative unmark_lead_meeting or stating when not to call it.

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