Get Rate Limit Status

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

Goes well beyond the annotations: it discloses that the data comes from the most recent API call (a staleness/freshness caveat), that the tool makes no Canvas call itself (so calling it costs nothing), and that Canvas throttles by cumulative request cost. Annotations already say readOnly/idempotent, so this is genuine added context.

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?

Three tight sentences: what it reports, how it behaves, and when to call it. The action-driving guidance is placed at the end where it motivates use, with zero redundant filler.

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?

There is no output schema, and the description compensates by enumerating the returned fields. For a zero-parameter read-only diagnostic, nothing an agent needs in order to call it correctly is missing.

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, which is the baseline-4 case. The description correctly implies no input is needed, though it does not explicitly state that the tool takes no arguments.

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 a specific verb and resource (report Canvas rate-limit state) plus exactly what it returns: remaining quota, last request cost, and session request count. It is unambiguous against siblings like check_token_expiry or test_connection, which cover different diagnostics.

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?

Explicitly tells the agent when to call it: before expensive tools such as semester_snapshot, justified by Canvas's cumulative-cost throttling. It does not name any when-not conditions, but the positive guidance is precise enough to drive selection.

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