calendar_today

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

No annotations are supplied, so the description carries the full burden. It does disclose the returned fields (date, weekday, semester, teaching week, events), which is valuable because there is no output schema, but it never states that the call is read-only, side-effect free, or how the current date is resolved (timezone, caching). For a zero-parameter informational lookup the risk is low, but the disclosure is incomplete.

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?

A single short sentence lists the returned values in a natural reading order, with the core resource ('today's date') front-loaded. No filler, no repetition of the tool name.

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 usefully enumerates the returned fields, which is the main thing an agent needs to know. The remaining gap is minor: no note on timezone/recency of the data or on the shape of the events list.

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?

The tool takes zero parameters, so there is no parameter meaning to add and the baseline of 4 applies. The description correctly focuses on what is returned rather than inventing argument semantics.

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 names a specific resource set: today's date, weekday, semester, teaching-week number, and today's campus calendar events. An agent can tell it apart from calendar_week, which is the obvious week-scoped sibling, without opening a schema. It stops short of an explicit contrast with that sibling, so it is clear but not maximally differentiated.

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 only implied by the word 'today' in the description; there is no statement of when to call this versus calendar_week or events_upcoming. The scope is narrow enough that the intent is inferable, but no alternative is named and no exclusions are given.

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