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elasticsearch7-mcp

by agrica

Servidor MCP de Elasticsearch 7.x

Servidor MCP para conectarte a tu clúster de Elasticsearch directamente desde cualquier cliente MCP (como Claude Desktop, Cursor).

[!IMPORTANT] Este fork está enfocado solo a Elasticsearch 7.x. Fija el cliente @elastic/elasticsearch 7.17, cuya comprobación de producto acepta servidores anteriores a la 7.14. Para un clúster de Elasticsearch 8.x, usa el proyecto upstream @awesome-ai/elasticsearch-mcp, del que se derive este fork: el cliente 8.x no puede comunicarse con un servidor 7.x, y viceversa.

Este servidor conecta a los agentes con tus datos de Elasticsearch mediante el Model Context Protocol. Te permite interactuar con tus índices de Elasticsearch a través de conversaciones en lenguaje natural.

Resumen de funcionalidades

Las herramientas se organizan en tres conjuntos. Solo el primero está siempre expuesto; los otros dos se activan mediante una variable de entorno, de modo que un despliegue de producción pueda ofrecer diagnósticos sin ofrecer borrados. La activación ocurre en el registro: una herramienta deshabilitada no aparece nunca en tools/list, así que el modelo no puede llamarla y no consume nada en el contexto del agente.

Siempre disponibles — lectura y escritura de datos

Clúster

  • elasticsearch_health: salud del clúster, opcionalmente hasta el nivel de índice.

  • cluster_info: nombre del clúster, versión de Elasticsearch y variante de build.

Operaciones con índices

  • list_indices: lista índices, filtrados por un comodín de Elasticsearch (log-*).

  • create_index: crea un índice con configuraciones y mapeos opcionales.

  • reindex: copia un índice, opcionalmente filtrado por una consulta o transformado por un script.

  • get_aliases: qué aliases apuntan a qué índices.

Mapeos

  • get_mappings: los campos de un índice, como rutas punteadas con sus tipos, y luego el mapeo en bruto.

  • create_mapping: crea o actualiza el mapeo de un índice.

Búsqueda y datos

  • search: ejecuta una búsqueda de query DSL, con resaltado inyectado en todos los campos de texto — incluidos los anidados — a menos que la consulta traiga su propio highlight.

  • count: cuántos documentos coinciden, sin transferir ninguno.

  • get_document: obtiene un documento por su id.

  • bulk: indexa muchos documentos a la vez.

Plantillas

  • create_index_template: crea o actualiza una plantilla de índice componible.

  • get_index_template: lee plantillas de índice.

Tareas

  • get_task: avance de una tarea de larga duración, como la que devuelve reindex.

ES_ADMIN_TOOLS=true — diagnóstico (solo lectura)

Estas herramientas solo leen, así que es seguro activarlas en producción — y ese es su propósito: un agente puede entonces explicar por qué un índice no está sano sin que nadie inicie sesión en el clúster.

  • explain_allocation: por qué un shard no está asignado, con la decisión de cada asignador.

  • list_shards: estado a nivel de shard, empezando por las copias que no están STARTED.

  • list_nodes: heap, CPU, carga y presión de disco por nodo.

  • get_index_stats: contadores por índice — tamaño, segmentos, indexación, búsqueda, merges.

  • get_index_settings: la configuración de un índice (refresh_interval, réplicas, bloques de solo lectura).

  • get_cluster_settings: configuración del clúster que fue sobrescrita en tiempo de ejecución.

  • list_tasks: qué está ejecutando el clúster actualmente.

ES_ALLOW_DESTRUCTIVE=true — irreversible

Está pensado para un entorno de staging y está desactivado por defecto, así que la producción no puede alcanzar estas herramientas en absoluto.

  • delete_index: elimina un índice y sus datos.

  • delete_document: elimina un documento por su id.

  • delete_by_query: elimina todos los documentos que coinciden con una consulta — asincrónico, devuelve un id de tarea y el borrado continúa en segundo plano.

  • delete_index_template: elimina una plantilla de índice.

Incluso con la bandera activada, estas herramientas rechazan un comodín, una lista separada por comas, * y _all: actúan sobre un solo índice con nombre a la vez. Un modelo que confunda logs-* con un índice único recibe un rechazo en lugar de un clúster vacío.

Cómo funciona

  1. El cliente MCP analiza tu solicitud y determina qué operaciones de Elasticsearch son necesarias.

  2. El servidor MCP lleva a cabo estas operaciones (listar índices, obtener mapeos, realizar búsquedas).

  3. El cliente MCP procesa los resultados y los presenta en un formato fácil de usar.

Related MCP server: Elasticsearch 7.x MCP Server

Primeros pasos

Requisitos previos

  • Una instancia de Elasticsearch 7.x (probada con 7.8; el cliente 7.17 es compatible desde 6.8 hasta 7.x).

  • Credenciales de Elasticsearch: una API key, o un nombre de usuario y una contraseña.

  • Un cliente MCP: Claude Code, Claude Desktop, Codex, Cursor, o cualquier otra cosa que hable MCP por stdio.

Autentícate en GitHub Packages, una vez

[!IMPORTANT] Este paquete se publica en GitHub Packages, no en npmjs.com, y GitHub Packages requiere un token incluso para paquetes públicos. Hasta que añadas uno, cada instalación de abajo fallará con un 401. Ponlo en tu ~/.npmrc de nivel de usuario:

@agrica:registry=https://npm.pkg.github.com
//npm.pkg.github.com/:_authToken=YOUR_GITHUB_TOKEN

YOUR_GITHUB_TOKEN es un personal access token con el ámbito read:packages.

Guárdalo en tu propio ~/.npmrc, y no en un archivo de proyecto: un token enviado a un repositorio es un token filtrado, y algunos gestores de paquetes se niegan a leerlo desde ahí.

Conéctalo a tu cliente

Cada ejemplo de abajo define ES_HOST y ES_API_KEY. Cambia ES_API_KEY por ES_USERNAME/ES_PASSWORD para autenticación básica, añade ES_ADMIN_TOOLS=true para obtener las herramientas de diagnóstico, y establece ES_INSTANCE_LABEL cuando declares más de una instancia; consulta Opciones de configuración.

claude mcp add elasticsearch7 \
  --env ES_HOST=https://your-cluster:9200 \
  --env ES_API_KEY=your-api-key \
  --env ES_ADMIN_TOOLS=true \
  -- npx -y @agrica/elasticsearch7-mcp

Después, /mcp en una sesión muestra el servidor y sus herramientas.

Dos detalles que son fáciles de equivocar:

  • Todo lo que está después de -- es el comando que ejecuta el servidor; sin él, Claude Code intentaría interpretar -y como una de sus propias opciones.

  • No pongas el nombre del servidor justo después de --env: la CLI lo lee como otro par KEY=value y lo rechaza. Arriba, el nombre va primero, que es por lo que funciona.

El servidor se agrega en el ámbito local, por lo que solo se carga en el proyecto actual. Añade --scope user para tenerlo en todas partes, o --scope project para escribirlo en .mcp.json y compartirlo con tu equipo: ten en cuenta que un .mcp.json enviado al repositorio contendría tu API key, así que prefiere el ámbito de usuario para las credenciales.

Edita claude_desktop_config.json: Settings > Developer > Edit Config lo abre, o encuéntralo en %APPDATA%\Claude\ en Windows y en ~/Library/Application Support/Claude/ en macOS:

{
  "mcpServers": {
    "elasticsearch7": {
      "command": "npx",
      "args": ["-y", "@agrica/elasticsearch7-mcp"],
      "env": {
        "ES_HOST": "https://your-cluster:9200",
        "ES_API_KEY": "your-api-key",
        "ES_ADMIN_TOOLS": "true"
      }
    }
  }
}

Reinicia Claude Desktop después; solo lee ese archivo al inicio.

codex mcp add elasticsearch7 \
  --env ES_HOST=https://your-cluster:9200 \
  --env ES_API_KEY=your-api-key \
  -- npx -y @agrica/elasticsearch7-mcp

O escríbelo a mano en ~/.codex/config.toml. Ten en cuenta que Codex escribe la tabla como mcp_servers, con un guion bajo, y que el entorno va en su propia sub-tabla, en lugar de en línea:

[mcp_servers.elasticsearch7]
command = "npx"
args = ["-y", "@agrica/elasticsearch7-mcp"]

[mcp_servers.elasticsearch7.env]
ES_HOST = "https://your-cluster:9200"
ES_API_KEY = "your-api-key"
ES_ADMIN_TOOLS = "true"

/mcp dentro de Codex confirma que el servidor está cargado.

El servidor es un servidor MCP de stdio normal, así que funciona con todo lo que es lista de clientes MCP. Necesita tres cosas: el comando npx, los argumentos -y @agrica/elasticsearch7-mcp y las variables ES_* en su entorno. Nunca escucha en un puerto y no escribe nada más que el protocolo MCP por stdout: los diagnósticos van a stderr.

Opciones de configuración

The Elasticsearch MCP Server admite opciones de configuración para conectarse a tu Elasticsearch:

[!NOTE] Debes proporcionar una API key o tanto nombre de usuario como una contraseña para la autenticación.

Variable de entorno

Descripción

Requerido

ES_HOST

La(s) URL(s) de tu instancia de Elasticsearch: admite una sola URL o varias separadas por comas (también acepta la heredada HOST)

Sí

ES_API_KEY

API key de Elasticsearch para la autenticación (también acepta la heredada API_KEY)

No

ES_USERNAME

Nombre de usuario de Elasticsearch para la autenticación básica (también acepta la heredada USERNAME)

No

ES_PASSWORD

Contraseña de Elasticsearch para la autenticación básica (también acepta la heredada PASSWORD)

No

ES_CA_CERT

Ruta al certificado CA personalizado para SSL/TLS de Elasticsearch (también acepta la heredada CA_CERT)

No

ES_REQUEST_TIMEOUT

Tiempo de espera por solicitud en milisegundos. Por defecto 30000: súbelo cuando las agregaciones sobre muchos índices se agoten.

No

ES_MAX_RETRIES

Reintentos por solicitud. Por defecto 3; 0 los desactiva.

No

ES_MAX_RESULT_BYTES

Tope máximo para el resultado de una herramienta. Por defecto 32768. Más allá de eso, se omite el detalle y el resultado lo dice.

No

ES_INSTANCE_LABEL

Nombre libre de texto para este despliegue, por ejemplo production. Se muestra como título del servidor, así que varias instancias declaradas una junto a otra se pueden distinguir.

No

ES_ADMIN_TOOLS

true para exponer también las herramientas de diagnóstico de solo lectura. Por defecto desactivado.

No

ES_ALLOW_DESTRUCTIVE

true para exponer también las herramientas irreversibles. Por defecto desactivado.

No

[!WARNING] ES_ADMIN_TOOLS y ES_ALLOW_DESTRUCTIVE no tienen un alias heredado sin prefijo, a diferencia de las variables de conexión anteriores. Esto es deliberado: un ADMIN_TOOLS o ALLOW_DESTRUCTIVE suelto en el entorno es demasiado fácil de activar por accidente para una característica que decide si los borrados son accesibles.

Ambas aceptan true o 1; cualquier otra cosa, incluida una variable sin definir, significa que está desactivado.

Tamaño del resultado

Un resultado de herramienta está limitado a 32 KB (ES_MAX_RESULT_BYTES). Esto importa en un clúster de registros: antes del límite, una sola llamada a list_shards sobre un año de índices diarios devolvía 385 KB (alrededor de 96 000 tokens) en una sola respuesta, más de lo que la mayoría de las sesiones pueden retener.

Cuando un resultado se recorta, el propio resultado lo dice, indica cuánto se recortó y explica cómo hacer una pregunta más pequeña. Tres herramientas adaptan sus respuestas:

  • list_indices y list_shards devuelven un resumen legible; las mismas filas con texto se obtienen con verbose.

  • search limita el size a 100 por llamada y te indica el from con el que paginar.

  • get_mappings enumera primero los campos y luego el mapeo en bruto, de modo que un índice con mil campos sigue respondiendo a la pregunta que se hizo.

Cuatro herramientas — list_indices, list_shards, get_index_settings y get_mappings — también devuelven su respuesta como salida estructurada y tipada, de modo que un cliente pueda leer las filas en lugar de interpretar el texto. Se compone con el espacio de la respuesta legible y devuelve returned contra total, para que un listado parcial se vea como número.

Ejecuta pnpm run measure sobre la versión construida para ver las cifras actuales de tu propia configuración.

Etiquetado de varias instancias

La mayoría de las configuraciones declaran este servidor más de una vez — una entrada por clúster. Por lo demás, las entradas son idénticas, así que un cliente muestra dos servidores con el mismo nombre y nada que los distinga. ES_INSTANCE_LABEL se convierte en el título visible del servidor, y es el lugar natural para decir qué entorno alcanza cada entrada:

{
  "mcpServers": {
    "es7-prod": {
      "command": "npx",
      "args": ["-y", "@agrica/elasticsearch7-mcp"],
      "env": {
        "ES_HOST": "https://es-prod:9200",
        "ES_API_KEY": "prod-key",
        "ES_INSTANCE_LABEL": "production",
        "ES_ADMIN_TOOLS": "true"
      }
    },
    "es7-staging": {
      "command": "npx",
      "args": ["-y", "@agrica/elasticsearch7-mcp"],
      "env": {
        "ES_HOST": "https://es-staging:9200",
        "ES_API_KEY": "staging-key",
        "ES_INSTANCE_LABEL": "staging",
        "ES_ADMIN_TOOLS": "true",
        "ES_ALLOW_DESTRUCTIVE": "true"
      }
    }
  }
}

Ese par es la forma prevista: diagnósticos en ambos, borrados solo en staging. Producción conserva las herramientas que explican un índice en mal estado y nunca expone una que pueda eliminar datos: el modelo no puede llamar a lo que nunca se registró.

La etiqueta también se imprime en stderr al inicio, que es donde hay que mirar cuando un cliente informa de una conexión pero no puedes saber qué clúster respondió.

Configuración de múltiples URLs

Puedes configurar varios nodos de Elasticsearch para alta disponibilidad y equilibrio de carga:

{
  "mcpServers": {
    "elasticsearch7-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@agrica/elasticsearch7-mcp"
      ],
      "env": {
        "ES_HOST": "https://es-node1:9200,https://es-node2:9200,https://es-node3:9200",
        "ES_API_KEY": "your-api-key"
      }
    }
  }
}

El cliente gestionará automáticamente la conmutación por error y el equilibrio de carga entre los nodos configurados.

Ejecución con Docker

Cada versión publica una imagen multiarquitectura (linux/amd64, linux/arm64) en el Registro de Contenedores de GitHub:

docker pull ghcr.io/agrica/elasticsearch7-mcp:latest

El servidor habla mediante stdio, así que el contenedor necesita un stdin interactivo y ningún puerto publicado. En un cliente MCP:

{
  "mcpServers": {
    "elasticsearch7-mcp": {
      "command": "docker",
      "args": [
        "run", "--rm", "-i",
        "-e", "ES_HOST",
        "-e", "ES_API_KEY",
        "ghcr.io/agrica/elasticsearch7-mcp:latest"
      ],
      "env": {
        "ES_HOST": "your-elasticsearch-host",
        "ES_API_KEY": "your-api-key"
      }
    }
  }
}

[!NOTE] Al igual que el paquete npm, la imagen vive en GitHub Packages: descargarla requiere un token con el ámbito read:packages, aunque el repositorio sea público.

La imagen no necesita ningún puerto publicado ni volumen: habla mediante stdio y el cliente MCP es dueño de su stdin y su stdout.

Consultas de ejemplo

[!TIP] Aquí tienes algunas consultas en lenguaje natural que puedes probar con tu cliente MCP.

Gestión del clúster

  • "¿Cuál es el estado de salud de mi clúster de Elasticsearch?"

  • "¿Cuántos nodos activos hay en mi clúster?"

Operaciones con índices

  • "¿Qué índices tengo en mi clúster de Elasticsearch?"

  • "Crea un nuevo índice llamado 'users' con 3 shards y 1 réplica."

  • "Reindexa los datos de 'old_index' a 'new_index'."

Gestión de mappings

  • "Muéstrame los mapeos de campos del índice 'products'."

  • "Añade un campo de tipo keyword llamado 'tags' al índice 'products'."

Operaciones de búsqueda y datos

  • "Busca todos los pedidos de más de 500 dólares del mes pasado."

  • "¿Qué productos recibieron la mayor cantidad de reseñas de 5 estrellas?"

  • "Importa en bloque estos registros de clientes al índice 'customers'."

Gestión de plantillas

  • "Crea una plantilla de índice para logs con el patrón 'logs-*'."

  • "Muéstrame todas mis plantillas de índice."

Diagnósticos (requiere ES_ADMIN_TOOLS=true)

  • "El índice 'logs-2026' está en amarillo: ¿por qué sus shards están sin asignar?"

  • "¿Está algún nodo cerca del umbral de llenado de disco?"

  • "¿Cuál de mis índices es el más grande y qué parte son documentos eliminados?"

  • "¿Alguien ha desactivado la asignación de shards en este clúster?"

  • "¿Sigue ejecutándose una reindexación?"

Destructivas (requiere ES_ALLOW_DESTRUCTIVE=true)

  • "Elimina el índice 'smoke-test-source'."

  • "Elimina todos los documentos anteriores a 2024 de 'logs-archive'."

Solución de problemas

Sintoma

Causa

npm error code E401 al instalar o con npx

No hay ningún token de GitHub Packages en tu ~/.npmrc a nivel de usuario. Consulta Autenticación en GitHub Packages.

Server error: ... invalid url al inicio

ES_HOST no está definido o está mal formado. Se valida en el inicio a propósito, en lugar de fallar más tarde en la primera consulta.

El cliente se conecta, pero falta una herramienta de diagnóstico o de borrado

Ese conjunto está limitado. Establece ES_ADMIN_TOOLS=true o ES_ALLOW_DESTRUCTIVE=true y reinicia el cliente.

Refusing to act on the pattern "logs-*"

Ess el comportamiento previsto: las herramientas destructivas aceptan un sola nombre de índice concreto, nunca un patrón, aunque la opción esté activada.

Un error de conexión que menciona la comprobación del producto

El clúster es 8.x o no es accesible. Esta compilación solo se comunica con 7.x.

¿Has encontrado un error o quieres una herramienta que no está? Abre un issue en el repositorio de GitHub. Para trabajar en el código, empieza por CONTRIBUTING.md.

Available Tools

17 tools
analyzeAnalyze textA
Read-onlyIdempotent

Show the terms a text is broken into, which is what a query must produce to match. Pass field with index to use the analyzer that index really applies to that field; that is the form that explains a search returning nothing.

ParametersJSON Schema
NameRequiredDescriptionDefault
textYesText to analyze
fieldNoUse this field's analyzer, taken from the index mapping.
indexNoIndex whose analyzers to use. Required with field.
analyzerNoNamed analyzer to test instead, e.g. standard, french.

TDQS

A4.2/5.0
Behavior3/5

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

Annotations already declare readOnly, idempotent, and non-destructive, so no safety disclosure is missing. The description adds semantic behavior: output is the token terms a query must match, and using field/index routes to the real per-field analyzer. It neither contradicts annotations nor reveals side-effect caveats beyond that, so a mid score is appropriate.

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?

Two compact sentences, the first states the core function and the second adds the key usage nuance. No filler or repetition of schema details.

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?

For a read-only diagnostic with one required parameter, the description plus schema covers what the tool does, how to choose a real-field analyzer, and why it matters for debugging searches. No output schema exists, but the description directly states the observable result ('terms a text is broken into'). It doesn't discuss response shape details, but they are unnecessary for basic invocation.

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

Parameters4/5

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

Schema coverage is 100%, so parameter basics are already documented. The description adds the important combination rule (field must be paired with index) and explains that the analyzer is taken from the index mapping, which is value beyond individual property docs. It earns an above-baseline score.

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 names a concrete operation — showing the tokenized terms produced from text — and ties it to query matching, so an agent understands what analyze returns. It also distinguishes the field/index form from a standalone analyzer test. This goes well beyond the vague title.

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?

It gives explicit guidance on the field-index combination as the way to use the actual analyzer applied by the index, and states this is the form that explains an empty search result. It doesn't explicitly enumerate alternatives or when to use the analyzer parameter, but the context is sufficient for a user to choose sensibly.

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

bulkBulk index documentsA

Index up to 1000 documents in one call. The index is refreshed by default, so they are searchable immediately; per-document failures are reported without failing the call.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesTarget index
idFieldNoField whose value becomes the document _id. Omit to let Elasticsearch generate ids.
refreshNoDefaults to true, making documents searchable at once. Set false when loading many batches: forcing a refresh per batch is the expensive part.
documentsYesDocuments to index, at most 1000. Send more in successive batches.

TDQS

A4.3/5.0
Behavior4/5

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

The description adds useful behavioral detail beyond the annotations: the index is refreshed by default so documents are immediately searchable, and per-document failures are reported without failing the whole call. This meaningfully informs the agent about side effects and error handling.

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?

Two sentences deliver the key information without redundancy: the action, the batch limit, the refresh behavior, and the failure handling. It is front-loaded with the most important operational constraint.

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

Completeness5/5

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

Given a complete input schema, a moderate number of parameters, and annotations covering the read/write profile, the description covers the important behavioral nuances—immediate searchability and partial failures. No critical information for invoking the tool correctly is missing.

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?

Schema description coverage is 100%, so the parameters are already well documented in the schema. The description reinforces the 1000-document limit and the default refresh behavior, but adds little semantic value beyond what the schema already states.

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 action ('Index'), a concrete resource ('documents'), and a clear constraint ('up to 1000 documents in one call'). This clearly separates it from siblings like create_index, create_mapping, and reindex, which target different operations.

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 establishes when bulk indexing is appropriate: when you have up to 1000 documents to index in a single call. It also explains the default refresh behavior, which helps an agent decide when to override it. It does not explicitly name alternatives, but the batching context is clear.

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

cluster_infoCluster version and identityA
Read-onlyIdempotent

Cluster name, Elasticsearch version and build flavour. The version decides which query DSL features exist.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

TDQS

A3.7/5.0
Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds useful context about the returned fields and the role of the version, but it does not disclose additional behavioral traits like response structure, authentication needs, or whether values are cached.

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 short sentences: the first front-loads the exact fields returned, and the second gives a brief reason the version matters. There is no filler or redundant restating of the title.

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?

For a parameterless, read-only metadata tool without an output schema, the description adequately covers what the agent gets (name, version, flavour) and why version is useful. It could be slightly richer by noting the response is a flat JSON object, but that is a minor omission for such a simple tool.

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

Parameters4/5

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

The tool takes zero parameters, so there is no parameter burden on the description. The schema is effectively empty and the baseline for 0 params is 4.

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

Purpose4/5

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

The description clearly identifies the resource (cluster identity: name, version, build flavour), but it uses a noun phrase rather than a specific verb like 'returns' or 'lists'. It is distinguishable from siblings by its focus on cluster metadata, yet it never explicitly differentiates itself from elasticsearch_health or other info tools.

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

Usage Guidelines3/5

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

The statement 'The version decides which query DSL features exist' implies when this tool is relevant: checking version-dependent DSL feature support. However, it does not explicitly say when to use it versus alternatives, nor does it mention any exclusions or prerequisites.

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

countCount documentsA
Read-onlyIdempotent

Count the documents matching a query, without transferring any. Cheaper than search when only the number matters.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesIndex to count in
queryNoQuery DSL. Omit to count every document.

TDQS

A4.5/5.0
Behavior4/5

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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds useful behavioral context beyond annotations: no documents are transferred and this operation is cheaper than search. This is meaningful information without contradicting the annotations.

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?

Two short sentences with no redundant words. The core action is front-loaded and the benefit/alternative is stated in the second sentence.

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

Completeness5/5

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

For a simple read-only counting tool, the description, schema, and annotations together cover the required parameters, the optional query behavior, the safety profile, and the use case. The return value (a count) is obvious from the tool's purpose, so no output schema is needed.

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?

Schema description coverage is 100%, so the schema already documents index and query, including that omitting query counts every document. The description does not add further parameter-level meaning but does not need to.

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 uses a specific verb-resource pairing ('Count the documents matching a query') and immediately differentiates from the sibling search tool by noting it transfers no documents. An agent can tell exactly what operation this performs and how it differs from search.

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

Usage Guidelines5/5

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

It explicitly states the condition for choosing count over search: 'when only the number matters,' and notes it is 'Cheaper than search.' The phrase 'without transferring any' also implies that search should be used when actual documents are needed.

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

create_indexCreate an indexA

Create a new index. Fails if it already exists — use create_mapping to add fields to an existing one.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesIndex name
mappingsNoField mappings, e.g. { properties: { title: { type: 'text' } } }
settingsNoIndex settings, e.g. number_of_shards, number_of_replicas

TDQS

A4.4/5.0
Behavior4/5

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

The description adds a valuable behavioral detail beyond the annotations: the operation fails rather than overwriting when the index already exists. This complements the annotations, which already indicate a non-read-only, non-idempotent write operation. It does not elaborate on all side effects, but the conflict behavior is the key operational trait.

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. It leads with the core action, then immediately states the failure condition and the correct alternative. Every sentence serves a distinct purpose and the structure makes it easy to scan.

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?

The description, together with the fully documented schema and annotations, provides enough context for correct invocation: required parameter, optional mapping/settings parameters, and the failure mode. It does not mention the create_index_template sibling, but that is not essential for invoking this specific tool correctly.

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?

All three parameters are already documented in the input schema, including examples for mappings and settings, so schema coverage is 100%. The description does not add additional parameter-level meaning, but it does not need to; the schema carries that burden effectively.

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 action and resource: 'Create a new index.' It also differentiates itself from the closest sibling, create_mapping, by explicitly saying to use that tool for adding fields to an existing index. The purpose is immediately clear and not a tautology.

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

Usage Guidelines5/5

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

The description gives explicit when-to-use guidance: use this tool for creating a new index. It also gives an explicit when-not-to-use and alternative: 'Fails if it already exists — use create_mapping to add fields to an existing one.' This leaves little ambiguity about which tool to select.

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

create_index_templateCreate or update an index templateA
Idempotent

Create or update a composable index template (Elasticsearch 7.8+). It applies only to indices created after it, never to existing ones.

ParametersJSON Schema
NameRequiredDescriptionDefault
nameYesTemplate name
versionNoVersion number, for your own tracking
priorityNoPrecedence when several templates match; higher wins
templateYesWhat to apply: { settings, mappings, aliases }
indexPatternsYesIndex wildcards the template applies to, e.g. ['logs-*']

TDQS

A4.2/5.0
Behavior4/5

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

Annotations already indicate a mutating, idempotent, non-destructive operation. The description adds important behavior beyond the annotations: the Elasticsearch 7.8+ requirement and the non-retroactive nature of the template. No contradiction exists between description and annotations.

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?

A single sentence communicates the action, resource, version constraint, and the most important behavioral caveat with no filler. The key scoping limitation is front-loaded and easy to parse.

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?

For a write tool with 5 parameters, a nested template object, and no output schema, the description covers the decisive behavioral constraint and version compatibility while relying on the fully documented schema for parameter details. It does not mention the response format, but that is a minor gap for a create/update tool.

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?

Schema description coverage is 100%, so all five parameters already have inline documentation. The description does not add substantial parameter-level meaning beyond the schema, making the baseline 3 appropriate.

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 ('Create or update') and a specific resource ('composable index template'), which clearly distinguishes it from sibling tools like create_index or create_mapping. The version qualifier and 'applies only to indices created after it' add further precision about what the tool does.

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 clear context: this tool is for defining templates that affect future indices only, and it explicitly states it never affects existing indices. It does not name alternative tools for existing-index changes, but the exclusion is clear enough for an agent to reason about when to use it.

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

create_mappingCreate or update a mappingA
Idempotent

Add or update fields on an index, creating the index if it does not exist. Elasticsearch cannot change the type of an existing field.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesIndex name
mappingsYesMapping to apply, e.g. { properties: { tags: { type: 'keyword' } } }

TDQS

A4.2/5.0
Behavior4/5

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

Annotations already indicate idempotent, non-read-only, and non-destructive behavior. The description adds valuable constraints beyond annotations, especially the critical limitation that 'Elasticsearch cannot change the type of an existing field', which helps agents anticipate failures.

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?

Two tightly written sentences. The first conveys the core action and index-creation behavior, and the second adds the most important caveat. There is no filler or repetition.

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?

For a two-parameter tool with a clear schema, the description covers the main behavioral caveat and typical usage. It does not describe the response shape, but given no output schema and the simplicity of the operation, the description is largely sufficient.

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?

Schema description coverage is 100%, with both parameters documented well; the mappings parameter even includes an example shape. The description itself adds no additional parameter-level detail, so the baseline of 3 is appropriate.

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 ('Add or update') and resource ('fields on an index') and clarifies that it can create the index if needed. This clearly differentiates it from sibling tools like get_mappings or create_index.

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 clear context: use this tool to mutate mappings, including when the index does not yet exist. It does not explicitly name alternatives or state when not to use it, but the operational scope is clear enough to guide selection.

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

elasticsearch_healthCluster healthB
Read-onlyIdempotent

Cluster health: status, node counts and shard counts.

ParametersJSON Schema
NameRequiredDescriptionDefault
includeIndicesNoAdd per-index health detail

TDQS

B3.4/5.0
Behavior3/5

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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the description does not need to re-establish safety. The description does add useful information about the return content (status, node counts, shard counts), which is helpful because there is no output schema. It does not add deeper behavioral context such as whether includeIndices changes response structure substantially, but that is partially covered by the parameter description.

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 one short, front-loaded sentence: 'Cluster health: status, node counts and shard counts.' Every word earns its place, and there is no redundancy or filler.

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?

For a simple read-only tool with zero required parameters and a well-documented optional parameter, the description covers the essential return content. The annotations cover the safety profile, and the schema covers the parameter. It is only missing explicit guidance for distinguishing it from cluster_info, which is already penalized under usage guidelines.

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?

Schema description coverage is 100%, and the only parameter, includeIndices, already has a meaningful description: 'Add per-index health detail'. The tool description adds no additional parameter semantics beyond the schema, so the baseline of 3 applies.

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

Purpose4/5

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

The description names the exact resource ('cluster health') and the specific output areas (status, node counts, shard counts), which makes the tool's purpose reasonably clear. It lacks an explicit verb like 'get', but the noun-phrase style with tool name 'elasticsearch_health' is sufficient. It is distinguishable from index-focused siblings like list_indices and get_mappings, though cluster_info could overlap without more detail.

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

Usage Guidelines2/5

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

The description gives no guidance on when to use this tool versus alternatives. With sibling cluster_info likely covering similar cluster-level information, the absence of a routing note is a real gap. Any usage guidance is only implied by the name and the word 'health'.

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

field_capsField capabilitiesA
Read-onlyIdempotent

Which fields exist across an index pattern and whether each is searchable and aggregatable. Takes a wildcard, unlike get_mappings, and is the only way to see a field mapped as two different types across indices — which makes an aggregation over it silently partial rather than failing.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesIndex, alias or wildcard, e.g. logs-app-*
fieldsNoField name or wildcard to ask about, e.g. log.* — comma-separated for several. Defaults to every field.

TDQS

A4.5/5.0
Behavior5/5

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: wildcard acceptance, cross-index type conflict visibility, and the non-obvious consequence that aggregations over such fields become silently partial rather than failing. This is exactly the kind of behavioral warning an agent needs.

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?

Two tight sentences: the first delivers the core purpose, the second adds the distinguishing behavior and its operational warning. Every clause earns its place, and the most decision-relevant information is front-loaded.

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

Completeness5/5

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

For a simple two-parameter, read-only tool, the description covers the essential facts: what it returns, how it differs from its sibling, and a critical edge-case consequence. The schema and annotations carry the remaining details, so nothing an agent needs to invoke it correctly is missing.

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 already describes both parameters clearly, including wildcard behavior and defaults, giving 100% schema description coverage. The description does not substantially add parameter-level meaning beyond that, so the baseline of 3 is appropriate; it reinforces the wildcard theme but introduces no new parameter detail.

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 opens with a precise statement of what the tool returns: fields across an index pattern plus whether each is searchable and aggregatable. It further distinguishes itself from get_mappings by calling out wildcard support and the special case of fields mapped as two different types, making the tool's identity unmistakable.

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 explicitly names get_mappings as the alternative and gives a concrete differentiator ('Takes a wildcard, unlike get_mappings'). It also establishes a strong when-to-use condition: it is the only way to detect a field mapped as two different types. It does not spell out the reverse case ('use get_mappings when...'), but the intended routing is clear.

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

get_aliasesList aliasesA
Read-onlyIdempotent

List which aliases point to which indices. A name you query may be an alias, which changes what get_mappings returns.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexNoIndex or wildcard. Omit for the whole cluster.

TDQS

A4.2/5.0
Behavior4/5

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

Annotations already declare readOnly, idempotent, non-destructive behavior. The description adds behavioral context by warning that aliases affect get_mappings results, which is useful beyond the annotations. No contradiction exists.

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?

Two sentences, no filler. The core purpose is front-loaded, and the second sentence adds valuable contextual information without unnecessary length.

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?

For a simple read-only tool with one optional parameter and no output schema, the description provides sufficient guidance. It could mention what the response contains, but the annotations and sibling context cover most operational concerns.

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?

Schema description coverage is 100%, so the optional 'index' parameter is already documented. The description doesn't add parameter-level detail beyond what the schema states, which matches the baseline for high schema coverage.

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 uses a specific verb and resource: 'List which aliases point to which indices.' It clearly communicates the tool's purpose and implicitly distinguishes it from sibling tools like list_indices and get_mappings.

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 concrete context for when this tool matters: when a queried name may be an alias and alters what get_mappings returns. It does not explicitly name alternatives or exclusion criteria, but the usage context is clear enough for an agent.

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

get_documentGet a document by idA
Read-onlyIdempotent

Fetch one document by its _id. Reports that it is absent rather than failing.

ParametersJSON Schema
NameRequiredDescriptionDefault
idYesDocument _id
indexYesIndex holding the document

TDQS

A4.2/5.0
Behavior4/5

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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds a meaningful behavioral trait beyond those annotations: it reports that a document is absent rather than failing. This tells the agent how missing documents are handled, which is useful for interpreting results.

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 short sentences with no wasted words. The core action is front-loaded, and the second sentence adds a useful behavioral note. It is concise without sacrificing important information.

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?

For a simple get-by-id tool with two fully documented parameters and strong annotations, the description is largely complete. It does not specify the exact return shape or concrete absent representation, such as null or an empty result, but 'Fetch one document' and 'Reports that it is absent rather than failing' cover the essential behavior an agent needs.

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?

Schema description coverage is 100%, so both parameters are already documented in the schema. The description adds little beyond the schema, aside from referring to '_id' in a way that maps to the id parameter. Baseline 3 is appropriate because the schema carries the parameter semantics.

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 and resource: 'Fetch one document by its _id.' It clearly distinguishes this from sibling tools like search or get_index_template by narrowing scope to a single document identified by _id. The additional detail about reporting absence rather than failing reinforces its unique purpose.

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 context: use this tool when you need exactly one document by its _id. It does not explicitly name alternatives or exclusions, but the stated single-document-by-id behavior is enough to imply the appropriate scenario and separate it from broader search or listing tools.

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

get_index_templateGet index templatesA
Read-onlyIdempotent

Get composable index templates. Omit name to list all.

ParametersJSON Schema
NameRequiredDescriptionDefault
nameNoTemplate name. Omit to list every template.

TDQS

A3.8/5.0
Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering safety semantics. The description adds the list-all behavior when name is omitted, but does not disclose output shape, errors, or other runtime behavior.

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 short, purposeful sentences with no filler. The main operation is front-loaded, and the optional-name behavior is expressed efficiently.

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?

For a simple, optional-parameter, read-only tool with strong annotations, the description is nearly complete. It could mention the return format or that it returns template definitions, but an agent has enough information to invoke it correctly.

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?

Schema description coverage is 100%, and the schema already explains that 'name' is optional and that omitting it lists every template. The description restates this without adding new semantic details, so the baseline score of 3 is appropriate.

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 clearly states the operation ('Get'), the resource ('composable index templates'), and the key behavior ('Omit name to list all'). This makes the tool's purpose immediately obvious and distinguishes it from create_index_template and other read-only sibling tools.

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

Usage Guidelines3/5

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

The description gives clear guidance on omitting the name to list all templates, but it does not explicitly discuss when to choose this tool over alternatives such as get_mappings or create_index_template. Usage context is mostly implied rather than stated.

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

get_mappingsGet index mappingsA
Read-onlyIdempotent

List the fields of one index as dotted paths with their types, nested fields included, then the raw mapping. Give a concrete index name: an alias or a wildcard returns nothing.

ParametersJSON Schema
NameRequiredDescriptionDefault
indexYesIndex name

Output Schema

ParametersJSON Schema
NameRequiredDescription
foundYes
indexYes
totalYes
fieldsYes
omittedYes
returnedYes

TDQS

A4.5/5.0
Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavior beyond annotations by specifying the output format (dotted paths with types, then raw mapping) and the alias/wildcard caveat, which is exactly the kind of context an agent needs.

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?

Two compact sentences front-load the tool's output behavior and then give the critical input constraint. Every sentence earns its place, with no filler or repetition of the schema.

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

Completeness5/5

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

Given the simple one-parameter schema, the presence of an output schema, and annotations covering safety, the description is complete. It explains what the response contains, when a call will succeed, and when it will return nothing.

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

Parameters4/5

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

The schema fully documents the single 'index' parameter with 100% coverage, so the baseline is 3. The description adds real semantic value by requiring a concrete index and warning that aliases and wildcards yield no results, which is not inferable from the schema alone.

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 action ('List the fields of one index as dotted paths with their types') and a concrete resource ('one index'), and it distinguishes the tool by noting nested fields are included and the raw mapping follows. This separates get_mappings from siblings like get_index_template or field_caps without requiring the agent to inspect schemas.

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 clear operational guidance: pass a concrete index name, and avoid aliases or wildcards because they return nothing. It does not explicitly name alternative sibling tools, but the precondition and failure mode are actionable enough for an agent to decide when to invoke this tool.

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

get_taskGet task progressA
Read-onlyIdempotent

Check an asynchronous task, such as the one reindex returns: progress, completion and failure.

ParametersJSON Schema
NameRequiredDescriptionDefault
taskIdYesTask id as returned by reindex, e.g. node-1:428

TDQS

A3.9/5.0
Behavior3/5

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

Annotations already declare the tool read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds that the task reports progress, completion, and failure, but it does not explain response format or polling behavior; this is modest added value beyond the annotations.

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 a single front-loaded sentence that names the action, the resource, the source of the task id, and the relevant outcomes. Every phrase earns its place with no redundant wording.

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

Completeness5/5

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

For a single-parameter polling tool with rich annotations, the description is complete: it says what to check, where the task id comes from, and what aspects are reported. No output schema exists, but the description names the key result dimensions well enough for correct invocation.

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 schema already provides 100% coverage for taskId, including its meaning and an example. The description only reinforces that the task id comes from reindex, adding no new parameter semantics beyond what the schema already supplies.

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

Purpose4/5

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

The description clearly states the tool checks an asynchronous task and identifies the specific scenario (tasks returned by reindex). It names the observable outcomes (progress, completion, failure), making the purpose unambiguous, though it does not explicitly differentiate from siblings.

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 provides a clear usage context: use this after an asynchronous operation such as reindex that returns a task id. It does not state when-not-to-use or name alternatives, but the context is concrete enough for an agent to select it appropriately.

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

list_indicesList indicesA
Read-onlyIdempotent

List indices, one compact line each: name, health, status, document count and size in bytes. Large results are trimmed and say so.

ParametersJSON Schema
NameRequiredDescriptionDefault
patternNoElasticsearch wildcard, e.g. `logs-*`. Not a regex. Defaults to `*`.
verboseNoAlso repeat the rows as JSON text, for a client that does not read structured output.

Output Schema

ParametersJSON Schema
NameRequiredDescription
totalYes
indicesYes
omittedYes
patternYes
returnedYes

TDQS

A4.3/5.0
Behavior4/5

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

The description goes beyond the read-only and idempotent annotations by disclosing the compact per-line format and the important trimming behavior for large results. This prevents an agent from assuming the output is always complete. Safety is already covered by annotations.

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?

Two short sentences front-load the purpose and output shape, then add the trimming caveat. Every phrase earns its place and there is no boilerplate.

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

Completeness5/5

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

With only two optional parameters, a full output schema, and annotations covering safety and idempotence, the description supplies the key behavioral caveat (trimming) and output fields. An agent has everything needed to invoke list_indices correctly.

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 already documents both parameters at 100% coverage, including the wildcard-vs-regex distinction for pattern and the purpose of verbose. The description adds no parameter-level detail, so the baseline score of 3 is appropriate.

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 operation ('List indices') and defines the exact output fields (name, health, status, document count, size in bytes), making it immediately distinguishable from sibling tools like get_mappings or field_caps. It clearly identifies the resource and the compact representation.

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 output description clearly implies its use case: obtaining a compact overview of indices with health and size information. It does not explicitly name sibling alternatives or state exclusions, so it falls just short of full routing guidance.

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

reindexReindex into another indexA

Copy documents between indices. Asynchronous: returns a task id at once and the copy is still running on return — poll it with GET _tasks/.

ParametersJSON Schema
NameRequiredDescriptionDefault
queryNoQuery DSL selecting which documents to copy. Omit to copy all.
scriptNoTransform each document while copying
destIndexYesDestination index, created if absent
sourceIndexYesSource index

TDQS

A4/5.0
Behavior4/5

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

The description goes beyond the annotations by disclosing the crucial asynchronous behavior: it returns a task id immediately while the copy continues, and it tells the caller how to poll progress. Annotations already cover read/write/destructive aspects, and the description adds meaningful operational context without contradicting them.

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?

Two tight sentences: the first states the action clearly, and the second adds the key behavioral caveat and how to follow up. No filler or repetition of schema content.

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?

For a tool with nested parameters and no output schema, the description explains the main return signal (task id) and the continuation mechanism. It is sufficient for an agent to select and invoke the tool correctly, though it does not detail edge cases or result formats beyond the task id.

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?

Schema description coverage is 100%, and the schema already documents sourceIndex, destIndex, query, and script with meaningful descriptions. The tool description adds no parameter-specific detail, but the schema carries that burden fully, so the baseline 3 is appropriate.

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 uses a specific verb and resource pair: 'Copy documents between indices.' This clearly distinguishes reindex from read-only search, single-document get, and indexing/bulk operations, and the title reinforces the same intent.

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

Usage Guidelines3/5

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

The description clearly implies when to use this tool: when documents must be copied between indices. However, it does not explicitly explain when not to use it or mention alternatives such as bulk for direct writes or search for read-only queries. The async polling hint gives practical usage context, but no explicit routing guidance.

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

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

  1. 17 tool updatesv0.4.1
    • First observedanalyze
    • First observedbulk
    • First observedcluster_info
    • First observedcount
    • First observedcreate_index
    • First observedcreate_index_template
    • First observedcreate_mapping
    • First observedelasticsearch_health
    • First observedfield_caps
    • First observedget_aliases
    • First observedget_document
    • First observedget_index_template
    • First observedget_mappings
    • First observedget_task
    • First observedlist_indices
    • First observedreindex
    • First observedsearch

TDQS

A3.7/5.0

Scored across 17 tools

Disambiguation5/5

Each tool targets a distinct operation or resource: field inspection is split cleanly between get_mappings and field_caps, with explicit notes about wildcard vs concrete index behavior. create_index, create_mapping, bulk, and reindex are also clearly differentiated, so an agent should not confuse them.

Naming Consistency3/5

Most tools use get_, list_, or create_ prefixes, but bare nouns and verbs like bulk, count, reindex, field_caps, cluster_info, and elasticsearch_health break the verb_noun pattern. Naming is readable and consistently snake_case, but the conventions are mixed.

Tool Count3/5

17 tools is on the heavy side for a single server and makes agent tool selection slightly harder. Each tool does map to a real Elasticsearch operation, so the count is not excessive, but it is borderline.

Completeness2/5

The surface covers health, mappings, search, indexing, and templates, but lacks delete/update operations for documents and indices, and has no deletion for aliases or templates. This creates significant dead ends for common lifecycle workflows.

Maintenance

ActivitySlowing
ResponsivenessNo issues

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