tool-lead
An advisory by default: it explains, and blocks nothing, on a description whose first sentence opens on the tool itself, holds under 4 words or runs past 40 words.
What it catches
A description whose first sentence opens on the tool itself, holds under 4 words or runs past 40 words.
Dimension
structure: the reader has to reconstruct the order or the purpose. A finding is counted on
the dimension of its rule, the cost it names to the reader.
Why
A 2026 study of 856 MCP tool descriptions found 56% did not state their purpose clearly, and a model choosing among many tools has only the description to go on. Over the 22 descriptions magus ships (6 MCP tools, 16 skills) the first sentence runs 7 to 45 words and none opens on "This tool" or on the tool's own name. 2 pass 40 words: magus-context-audit (42) and magus-diagram (45), each a list of nouns before the verb's object. The rule only advises, since 2 firings are too few to deny on.
Default decision
The code is PRF9020. The decision depends on the kind of text judged:
| Kind | Default |
|---|---|
tool-description |
advise |
Changing it
A decisions table sets this rule to deny, advise or off, for everything judged
or for the files a glob matches. Proofread reads the table from the file its
-decisions flag names:
{
"rules": {"tool-lead": "deny"},
"paths": {"blog/**": {"tool-lead": "off"}}
}
rules applies to every file. A glob in paths applies to the files it matches, and the
last match wins. A rule set to off never reports.
Seeing it
A finding names the rule, its code and the decision that applies, and links here:
{"rule": "tool-lead", "code": "PRF9020", "decision": "advise", "url": "https://eli.gladman.cc/magus/reference/proofread/tool-lead/"}
proofread rules prints this entry with every other rule's.
See also
- All proofread rules - every rule, grouped by what it checks
- Writing rules - how the rules apply to this repository's pages and pull requests
- The findings contract - the fields every finding carries