alma-corpus-mcp

flux_recovery

Estimate the fraction of smooth-source flux recovered on the shortest baseline for Gaussian or uniform-disk sources, and find sizes where recovery drops to 0.5 and 0.1.

Instructions

Rough fraction of a smooth source's total flux still seen on the shortest baseline.

gaussian (size = FWHM): V(q)/V(0) = exp(-pi^2 theta^2 q^2 / (4 ln 2)); uniform_disk (size = diameter): 2 J1(pi D q)/(pi D q); q = B_min / lambda. Also gives the source sizes at which this fraction falls to 0.5 and 0.1. This is a note, not a measurement: actual recovery depends on the full uv coverage and on deconvolution, and is usually worse for extended emission. Remedy: add ACA 7 m and total power data.

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": {
      "source_size_arcsec": "<source_size_arcsec>",
      "freq_ghz": "<freq_ghz>",
      "b_min_m": "<b_min_m>"
    },
    "name": "flux_recovery"
  }
}

Input Schema

Name	Required	Default
`shape`	No	gaussian
`b_min_m`	Yes
`freq_ghz`	Yes
`source_size_arcsec`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 9, 2026

TDQS

A3.8/5.0

Behavior4/5

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

No annotations are provided, so the description carries the full behavioral burden. It does well by disclosing that this is a rough approximation rather than a measurement, that extended emission is usually worse, and that additional ACA/total power data may be needed. It does not specify exact return keys or input constraints, which keeps it from a 5.

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?

The definition is front-loaded with the core purpose, followed by formulas and then caveats. The equations are dense but relevant because the schema has no parameter descriptions; there is little filler, though the notation could be slightly tighter for agent readability.

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 four-parameter calculation tool with no output schema, the description explains the computed quantity, the formulas, the caveats, and the auxiliary 0.5/0.1 size outputs. It still leaves exact return structure and units implicit, which is a minor gap rather than a blocking one.

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 description coverage is 0%, so the description must compensate, and it largely does: it defines source_size_arcsec as FWHM for gaussian and diameter for uniform_disk, introduces B_min and lambda through q = B_min / lambda, and names the two shape variants. It does not explicitly restate freq_ghz units or enumerate all accepted shape values, so it is not fully complete.

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 specifically states that it computes the rough fraction of a smooth source's total flux still seen on the shortest baseline, and it also says it returns source sizes where the fraction falls to 0.5 and 0.1. It does not explicitly distinguish itself from sibling tools such as largest_angular_scale or fit_uv_model, so it falls short of a 5.

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 an important usage caveat: 'This is a note, not a measurement,' and explains that actual recovery depends on uv coverage and deconvolution. It also offers a remedy, but it does not name alternative tools or explicitly say when to choose this calculation over siblings, so usage is implied rather than clearly routed.

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