Galaxy Cluster Catalogs MCP Server

plot_mass_redshift

Overlay galaxy-cluster catalogues in the M500–z plane to compare SZ and X-ray selection effects and identify how survey coverage differs across mass and redshift.

Instructions

Overlay several cluster catalogues in the M500-z plane (the standard selection-function picture).

Use to show how SZ (flat-in-M at high z) and X-ray (flux-limited, low z, low mass) selections differ. Only entries with both z and M500 are drawn.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "output_dir": "<output_dir>",
      "catalogs": "<catalogs>"
    },
    "name": "plot_mass_redshift"
  }
}

Input Schema

Name	Required	Description	Default
`stem`	No	Output file stem.	mass_redshift
`z_max`	No	Upper x limit.
`catalogs`	Yes	Harmonised CSVs from fetch_cluster_catalog and/or dataset keys (full catalogue).
`log_mass`	No	Log M500 axis.
`output_dir`	Yes	Directory for the PNG.
`marker_size`	No	Scatter marker size.

Output Schema

Name	Required	Description	Default
`files`	Yes
`status`	Yes
`message`	Yes
`metadata`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 6, 2026

TDQS

A3.9/5.0

Behavior3/5

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

No annotations are supplied, so the description carries the burden. It usefully discloses the filtering rule ('Only entries with both z and M500 are drawn'), but says nothing about missing-file handling, errors, or what the output artifact looks like (that is partly covered by the output schema).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

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

Three short lines, front-loaded with the core action and the physical picture, then the rationale and the row-filtering constraint. There is no filler, though the parentheticals are slightly wordy.

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?

With a 100%-covered schema and an output schema, the description only needs to convey intent and data requirements, which it does. It could say more about how multiple catalogues are visually distinguished, but nothing an agent needs in order to invoke it 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 coverage is 100%, so the schema already documents every parameter. The description only adds that catalogues must carry both z and M500 to be drawn, which slightly enriches the 'catalogs' semantics but adds nothing on stem, z_max, log_mass, marker_size, or output_dir.

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 ('Overlay several cluster catalogues in the M500-z plane') and frames it as the standard selection-function picture, which distinguishes it from sibling plotting tools such as plot_cluster_sky_map or plot_completeness.

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 a clear when-to-use rationale ('Use to show how SZ (flat-in-M at high z) and X-ray (flux-limited, low z, low mass) selections differ'), but names no explicit alternative or exclusion condition for choosing another plotting tool.

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