plot_cluster_sky_map

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

With no annotations, the description carries the full burden, and it does disclose the meaningful behavioural facts: the Mollweide projection, that RA increases to the left by astronomical convention (which affects how output must be interpreted), and that the input set can span multiple catalogues. It leaves gaps on file-level behaviour such as whether an existing PNG with the same stem is overwritten or how missing catalogues are handled, which keeps it below 5.

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

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

Two short paragraphs, front-loaded with what is produced and followed immediately by the usage scenario; nothing is padded. The parenthetical list of four survey footprints is slightly long, but each example illustrates a distinct overlap case, so it largely earns its place.

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

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

For a plotting tool with six parameters, full schema coverage and an output schema, the description supplies enough to select and invoke it correctly: purpose, projection, input expectations and workflow position. Only minor behavioural details (overwrite semantics, error handling for bad catalogue paths) are absent, which the output schema does not compensate for.

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

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

Schema description coverage is 100%, so every parameter (stem, coords, catalogs, color_by, output_dir, marker_size) is already documented in the schema, establishing a baseline of 3. The description adds only indirect nuance — that multiple catalogues are plotted together as overlapping footprints — and does not explain the color_by or coords choices beyond what the schema provides.

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

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

States a specific verb+resource combination (Mollweide sky map of one or more cluster catalogues) and adds the projection/orientation convention so the agent knows exactly what artefact is produced. This is clearly distinguishable from the other plotting siblings such as plot_mass_redshift, plot_completeness and plot_counts_vs_prediction.

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

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

Explicitly says when to use it: 'to show footprints and overlaps ... before a crossmatch', which ties it to the crossmatch_catalogs workflow. Concrete survey examples (SPT south, ACT equatorial strip, eRASS1, Planck all-sky) make the intended scenario tangible. No explicit when-not guidance or alternatives are named, so it falls short of a 5.

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