Announcements

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

Annotations already cover read-only and open-world access, so the description's job is lighter. It adds genuinely useful behavior: the default scope is all active classes, results include a direct Classroom link, and no filter means every 'recent' announcement. The vague boundary of 'recent' is left undefined.

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?

Front-loaded with what the tool returns, then scoping, then the user-intent examples. The scoping sentence partially duplicates the schema but the example queries earn their place; minor redundancy keeps it below 5.

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?

With no output schema, the description carries return-value burden and does describe the link-carrying shape, though it omits other announcement fields, ordering, and any result cap. Combined with annotations, this is enough for an agent to call it correctly, with minor unknowns.

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 coverage is 100%, so both parameters are fully documented in the schema, including the get_my_courses lookup hint. The description restates the same filtering intent without adding format, syntax, or interaction details, so baseline 3 applies.

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 the resource precisely ('Recent announcements') and even the return shape ('each with a link to open it in Classroom'). It is distinguishable by resource from siblings such as get_course_materials and get_whats_new, though it never explicitly contrasts with get_whats_new, which could plausibly overlap.

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?

Gives concrete trigger phrasing ('Did my teacher post anything new?') and explains the scoping choice: pass course_ids or since_days, or leave empty for all active classes. It lacks an explicit when-not-to-use or a named alternative, so it stops 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.