Improve documentation for agent parameters

Author: tsmbland

docs/inputs/agents.rst

@@ -218,7 +218,12 @@ Quantity
    A factor used to determine the demand share of "New" agents.
 
 MaturityThreshold (optional)
-   Required when using the :py:func:`maturity <muse.filters.maturity>` search rule.
+   Only applies when using the :py:func:`maturity <muse.filters.maturity>` search rule.
+   Allows agents to only consider technologies that have achieved a certain market share
+   (e.g. if 0.5, the agent will only invest in technologies that have a current market share of 50% or more).
+   Must be between 0 and 1.
 
 SpendLimit (optional)
-   Required when using the :py:func:`spend_limit <muse.filters.spend_limit>` search rule.
+   Only applies when using the :py:func:`spend_limit <muse.filters.spend_limit>` search rule.
+   Allows agents to only consider technologies with a unit capital cost (`cap_par`) lower than the spend limit.
+   (e.g. if 10, the agent will only invest in technologies with a `cap_par` of 10 or lower, as listed in the :ref:`inputs-technodata` file).

src/muse/filters.py

@@ -366,13 +366,10 @@ def spend_limit(
     enduse_label: str = "service",
     **kwargs,
 ) -> xr.DataArray:
-    """Only allows technologies that have achieve a given market share.
-
-    Specifically, the market share refers to the capacity for each end- use.
-    """
-    spend_limit = agent.spend_limit
+    """Only allows technologies with a unit capital cost lower than the spend limit."""
+    limit = agent.spend_limit
     unit_capex = agent.filter_input(technologies.cap_par, year=agent.year)
-    condition = (unit_capex <= spend_limit).rename("spend_limit")
+    condition = (unit_capex <= limit).rename("spend_limit")
     techs = (
         condition.technology.where(condition, drop=True).drop_vars("technology").values
     )