alma-corpus-mcp

frank_profile

Fits a non-parametric 1D radial brightness profile to interferometric visibilities using fixed geometry, returning radius, intensity, and 1-sigma uncertainties.

Instructions

Non-parametric 1D radial brightness profile with frank (Jennings et al. 2020), if installed.

Wraps frank.radial_fitters.FrankFitter with a FixedGeometry (inclination, PA east of north, offsets). alpha (1.05 default, papers use 1.01-1.3) and weights_smooth (1e-4 default, 1e-1 to 1e-4 used) set the Gaussian-process prior; report both. Returns r (arcsec), I (Jy/sr) and 1-sigma errors. Limits: frank assumes axisymmetry; its uncertainties are likely underestimated; the innermost 1-2 beams are least reliable; visibility weights must be correctly scaled first. Without frank installed this returns the install command.

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": {
      "vis_path": "<vis_path>",
      "inclination_deg": "<inclination_deg>",
      "pa_deg": "<pa_deg>"
    },
    "name": "frank_profile"
  }
}

Input Schema

Name	Required	Default
`alpha`	No
`pa_deg`	Yes
`uv_unit`	No	lambda
`freq_ghz`	No
`n_points`	No
`vis_path`	Yes
`dra_arcsec`	No
`ddec_arcsec`	No
`r_max_arcsec`	No
`weights_smooth`	No
`inclination_deg`	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?

With no annotations, the description carries the full burden and does well: it discloses the returned quantities and units (r in arcsec, I in Jy/sr, 1-sigma errors) and a graceful degradation path (returns the install command if frank is absent). It also flags systematic reliability limits that a caller must propagate. It does not say whether files are written or how long the fit takes, which is the main remaining gap.

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 description is dense but front-loaded: what it does, then prior parameters, then return values, then limits and fallback. Sentences are information-bearing rather than filler. It is somewhat cluttered by parenthetical numeric ranges and could be tightened, but nothing is clearly wasteful.

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

Completeness3/5

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

For an 11-parameter scientific fitting tool with no annotations and no output schema, the description covers the scientific semantics, return values, and failure mode well. It is still incomplete: r_max_arcsec and n_points directly control the radial grid and are unexplained, as are uv_unit and freq_ghz, which matter for correct visibility handling. An agent could call it but could easily set the gridding parameters wrongly.

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 0%, so the description must compensate for 11 bare parameters. It adds real meaning for alpha (default 1.05, literature range 1.01-1.3, prior-setting role) and weights_smooth (1e-4 default, 1e-1 to 1e-4 used), and implicitly covers inclination, PA east of north, and the two offsets via FixedGeometry. However, vis_path, uv_unit, freq_ghz, n_points, and r_max_arcsec are never explained, leaving roughly half the parameters undocumented anywhere.

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 a specific method and product: a non-parametric 1D radial brightness profile fitted with frank via FrankFitter plus a FixedGeometry. It is concrete about the physics output (r, I, 1-sigma errors), but it never names or contrasts with likely-confusable siblings such as fit_uv_model or deproject_and_bin, so an agent must infer the boundary.

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 strong implicit when-to-use and when-not-to-use context: axisymmetry is assumed, uncertainties are likely underestimated, the innermost 1-2 beams are unreliable, and visibility weights must be correctly scaled before calling. What is missing is an explicit routing statement (e.g. use fit_uv_model for parametric or non-axisymmetric fits), so the alternative-selection guidance is left to inference.

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