Proxy status

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

Annotations establish the safety profile (readOnly, idempotent, non-destructive), so the bar is lower, and the description adds real operational context beyond them: it reads from a *running* proxy and depends on GUARDIAN_HOST:GUARDIAN_PORT being configured. It does not mention failure modes when the proxy is unreachable.

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 short sentences with zero filler; the resource and its reported contents come first, the operational dependency last. 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?

With no output schema and no parameters, the description carries the return-value burden and does so by listing the status categories reported. It is complete enough to call correctly, though the categories (e.g. 'calibration', 'rejected summaries') are left unexplained.

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 no parameters, so there is nothing for the description to disambiguate — baseline 4 applies. The only configurable input is ambient (the host/port env vars), which the description appropriately surfaces.

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 — Context Guardian's live status from the running proxy — and enumerates the content it reports (window/budget, compactions, tokens saved, rejected summaries, calibration). It clearly differs from the read-oriented siblings search_spans and read_span, though it never explicitly contrasts itself with them.

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: you call this to inspect the proxy's current state. The mention of GUARDIAN_HOST:GUARDIAN_PORT hints at the operational prerequisite (a reachable running proxy), but there is no explicit when-to-use or when-not-to-use guidance relative to alternatives.

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