Casefile

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register_participant

Registers a human or permanent agent in a case file, assigning a unique name and optional description. Enables main token holders to add participants for tracking decisions and actions.

Instructions

Registers a human or a permanent agent. Only a main token registers participants; the new participant's token is issued through the REST API. An existing participant's description is changed by update_participant.

Input Schema

TableJSON Schema

Name	Required	Description
`kind`	Yes	Human or permanent agent
`name`	Yes	Name of the new participant: a Latin letter followed by 1–63 Latin letters, digits or `_` (`invalid_participant_name` otherwise). It is stored lower-case and never changes: it signs the participant's entries. A name already taken, in any case, is refused with `participant_name_taken`
`description`	No	Who the participant is: all that a reader of a case learns about the author of an entry
`idempotency_key`	No	Retry key chosen by the caller, e.g. a UUID. A repeat with the same key and the same arguments returns the first result and creates nothing; the same key with other arguments is refused with `idempotency_key_reused`. A key is bound to the caller's token and kept for 24 hours

Output Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed17 schema fields changedv0.5.2Sep 25, 2026

removedInput schema / $defs

Removed value: -{
-  "ParticipantKind": {
-    "description": "Род участника.\n\nРолей и прав за родом не стоит: любую запись и любой переход может сделать участник\nлюбого рода (`CONCEPT.md`, 3.1). Род нужен, чтобы читающий дело понимал, кто\nговорит, и чтобы интерфейс человека отличал людей от агентов в списке адресатов.",
-    "enum": [
-      "human",
-      "agent"
-    ],
-    "title": "ParticipantKind",
-    "type": "string"
-  }
-}

changedInput schema / properties / description / description

Previous value: -"Кто это. Всё, что читающий дело узнает об авторе записи"New value: +"Who the participant is: all that a reader of a case learns about the author of an entry"

removedInput schema / properties / description / examples

Removed value: -[
-  "Релизный бот, ведёт задачи выкладки"
-]

changedInput schema / properties / idempotency_key / description

Previous value: -"Ключ повтора, который ты придумываешь сам (обычно UUID). Повтор вызова с тем же ключом и теми же аргументами отвечает первым результатом и второго объекта не заводит; тот же ключ с другими аргументами отклоняется. Ключ живёт в паре с твоим токеном и помнится 24 часа"New value: +"Retry key chosen by the caller, e.g. a UUID. A repeat with the same key and the same arguments returns the first result and creates nothing; the same key with other arguments is refused with `idempotency_key_reused`. A key is bound to the caller's token and kept for 24 hours"

removedInput schema / properties / kind / $ref
```
Removed value: -"#/$defs/ParticipantKind"
```

changedInput schema / properties / kind / description

Previous value: -"Человек или постоянный агент"New value: +"Human or permanent agent"

addedInput schema / properties / kind / enum

Added value: +[
+  "human",
+  "agent"
+]

removedInput schema / properties / kind / examples
```
Removed value: -[
-  "agent"
-]
```
addedInput schema / properties / kind / type
```
Added value: +"string"
```

changedInput schema / properties / name / description

Previous value: -"Имя участника из реестра. Регистр не важен"New value: +"Name of the new participant: a Latin letter followed by 1–63 Latin letters, digits or `_` (`invalid_participant_name` otherwise). It is stored lower-case and never changes: it signs the participant's entries. A name already taken, in any case, is refused with `participant_name_taken`"

removedInput schema / properties / name / examples
```
Removed value: -[
-  "release_bot"
-]
```

removedOutput schema / $defs

Removed value: -{
-  "ParticipantKind": {
-    "description": "Род участника.\n\nРолей и прав за родом не стоит: любую запись и любой переход может сделать участник\nлюбого рода (`CONCEPT.md`, 3.1). Род нужен, чтобы читающий дело понимал, кто\nговорит, и чтобы интерфейс человека отличал людей от агентов в списке адресатов.",
-    "enum": [
-      "human",
-      "agent"
-    ],
-    "title": "ParticipantKind",
-    "type": "string"
-  }
-}

changedOutput schema / description

Previous value: -"Участник реестра: кому можно адресовать вопрос и что о нём известно."New value: +"Participant name in its stored, lower-case form; the registry is returned by\n`list_participants`."

removedOutput schema / properties / description

Removed value: -{
-  "title": "Description",
-  "type": "string"
-}

removedOutput schema / properties / kind

Removed value: -{
-  "$ref": "#/$defs/ParticipantKind"
-}

changedOutput schema / required

Previous value: -[
-  "kind",
-  "name",
-  "description"
-]New value: +[
+  "name"
+]

changedOutput schema / title

Previous value: -"ParticipantView"New value: +"ParticipantNameView"

First observedSep 23, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=false (mutation) and idempotentHint=false, so the description does not need to repeat that. It adds valuable context: the requirement for a `main` token and that the token is issued via REST API, which are behaviors not covered by annotations. This supplements the annotation profile 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.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with no filler. The first sentence states the core purpose, and the second sentence adds a constraint and differentiates from a sibling tool. Every clause earns its place, and the most important information is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (4 params, output schema present, minimal annotations), the description covers the essential purpose, token issuance, and differentiates from update_participant. It does not explain return values, but the output schema handles that. It omits potential side effects beyond token issuance, but that is a minor gap; an agent can call it correctly with the information provided.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 100% description coverage for all four parameters, including detailed explanations of `name`, `description`, and `idempotency_key`. The description adds no additional parameter-level semantics, so it neither improves nor degrades what the schema already provides. The baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Registers') and resource ('a human or a permanent agent'), and explicitly differentiates itself from update_participant by noting that an existing participant's description is changed by that tool. This makes it unmistakable that register_participant is for creating new participants, distinguishing it from siblings like update_participant and list_participants.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives a clear usage condition: only a `main` token can register participants, and the new participant's token is issued via the REST API. It also points to update_participant for changing descriptions, implying this tool is for new registrations. However, it does not explicitly list when not to use it or fully describe alternative selection criteria, leaving some room for inference.

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