get_usage

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

Well beyond the readOnlyHint annotation, the description discloses that the 'latest' field is fetched from GitHub at most once per day (a rate-limited network call), and that the tool records state when returning notified=false. Those are exactly the non-obvious traits an agent needs. The internal bookkeeping write is in mild tension with readOnlyHint but is framed as non-destructive notification tracking, so it reads as disclosure rather than contradiction.

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?

Almost every clause carries real information, but it is delivered as one dense run-on paragraph with stacked nested parentheses (profit: 利用枠…（…）・…（…）), which makes it hard to scan. Splitting the status fields from the version fields into separate sentences would cost nothing and gain a lot.

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 the full return-value burden and largely succeeds: it names each field group and explains the ambiguous ones (version sub-fields, profiles null semantics). Only the dense packaging and the missing 'call before start_session' framing keep it from a 5.

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?

Zero parameters, so the baseline of 4 applies. The description instead spends its words on output-field semantics — what null means for pauseAtPct and for profiles in start_session versus send_message — which is useful but belongs to the return contract, not parameter interpretation.

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 concrete read operation and enumerates the specific payload: per-window usage rate and reset time, free memory, running-conversation count, canStartNew plus reason, and watchIntervalMin. That is far more specific than a tautology, and no sibling (list_sessions, report, wait_events) covers this status surface. It loses a point because the purpose statement is buried under an equally long version-field enumeration, so the primary 'what' is not front-loaded.

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?

There is no explicit 'call this when…' or 'use X instead' routing; the reader must infer that this is the pre-flight check before start_session. What guidance exists is operational rather than selection-oriented: pauseAtPct null means do not stop on quota, and the notified/reloadNeeded/updateAvailable combination dictates telling the user. Implied rather than stated usage earns a middle score.

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