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

Annotations only indicate readOnlyHint=false, but the description adds significant behavioral context: it runs vector recall + model judgment, takes tens of seconds, costs money, sets the plan to a 'pending review' pause state, and returns 'exits' when no new person is found. This goes well beyond the annotations and discloses side effects and performance characteristics without contradiction.

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?

The description is structured with clear sections (when to use, combination chain, scope) and front-loaded with the primary usage condition. It is dense but each part is informative and necessary given the tool's complexity. Slightly lengthy but not wasteful, earning a 4.

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?

Covers login and organizer requirement, when to use, side effects (cost, time, plan state change), and an edge case (exits on no results). No output schema exists, but the description provides sufficient operational detail for an agent to decide and call it correctly. Minor gaps like full return structure do not impede usage.

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 both parameters are fully described (role enum with default and restriction, activityRef with source). The description reiterates the role constraint but adds no new parameter meaning beyond the schema. A baseline of 3 is appropriate since the schema carries the semantic weight.

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 clearly states it appends a batch of guest candidates for SPEAKER without reordering existing ones. It distinguishes from update_guest_candidates by specifying it only adds, and from set_guest_invite_plan by placing it in a workflow chain. The verb+resource is specific and unambiguous.

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?

Explicitly states when to use ('when existing candidates are insufficient or mismatched'), restricts to SPEAKER only, and provides a combination chain with set_guest_invite_plan and get_activity_invites. It also warns against calling twice consecutively due to cost, giving clear when-to-use and when-not-to-use guidance.

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