list_courses_by_weekday

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

With no annotations, the description carries the full burden and does it well: it discloses accepted weekday input forms (周一/星期一/Mon/1), returns sorted by class time, specifies the exact returned fields (course number, name, teacher, period time, location, credits), and states the empty-day behavior with a prompt message. This is substantial behavioral context beyond the raw schema.

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 compact sentences with zero filler: the purpose is front-loaded in a parenthetical, and the second sentence packs parameter flexibility, ordering, return fields, and the empty case. Every clause 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 simple one-parameter tool with an output schema, the description is nearly complete: it covers purpose, accepted input formats, output contents, ordering, and the empty result case. The only gaps are lack of sibling differentiation and unspecified behavior for invalid/unsupported weekday strings, both minor for a query tool of this simplicity.

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 0%, so the description must compensate, and it does: it explains that weekday accepts common representations such as 周一, 星期一, Mon, and 1, giving an agent concrete calling guidance the schema alone cannot. It loses a point for the open-ended '等常见写法' and no statement of what happens with unsupported input.

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: 查询星期几有哪些课 (query which courses fall on a given weekday), clarifying it is the schedule-by-day tool. This is clearly distinct from siblings like get_course or get_teacher, though it doesn't explicitly name or contrast them, so it stops short of a 5.

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?

Usage is implied: when an agent needs a given day's timetable, this tool fits. However, there is no explicit guidance about when to prefer it over search_courses or list_assignments, and no exclusions or routing among the four sibling tools.

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