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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true) and an output schema documents the return shape, so the description's job is to add what structured fields can't. It does so by disclosing the urgency sort order, the 'now onward' time boundary, and the non-obvious behavior that results may include activity types absent from sibling tools. It stops short of noting pagination behavior or how 'urgency' is computed, which keeps it below 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.

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

Roughly two sentences, front-loaded with what the tool returns and immediately followed by the differentiator against alternatives. No restated title, no filler, and the parenthetical examples carry real information.

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 read-only, one-optional-parameter tool with a published output schema and read-only/open-world annotations, nothing an agent needs in order to select and invoke it correctly is missing. Selection rationale, ordering, time window, and coverage relative to siblings are all present.

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?

With a single optional parameter at 100% schema description coverage, the schema already explains 'limit' fully, so the baseline is 3 by the rubric. The description earns a small upgrade because 'from now onward' and 'sorted by urgency' clarify the semantics of what is being limited — an urgency-ordered forward-looking window rather than an arbitrary page — which is genuinely additive context for calling the tool with a sensible limit.

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?

The description states a specific verb and resource — 'Get Moodle's own "what needs action soon" feed' — with concrete examples (assignments due, video lectures with a watch deadline) and an ordering rule (sorted by urgency, from now onward). It also explicitly distinguishes itself from the nearest alternative (combining list_assignments + get_calendar_events), so an agent can separate it from siblings without opening schemas.

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?

It names the alternative approach — combining list_assignments + get_calendar_events — and states the condition under which this tool is better: it is Moodle's own cross-activity prioritized view and may surface activity types (e.g. vod watch deadlines) that those tools miss. That is an explicit use-this-not-that rule rather than implied usage.

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