CGM data inventory

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds little beyond naming the returned content (metric catalog, TIR ranges, GMI formula) — which is more purpose than behavior. No contradictions, but no additional behavioral disclosure (e.g., privacy implications of the privacy_mode param) beyond what the schema already states.

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 sentence with the core purpose front-loaded ('Returns the metric catalog plus thresholds') followed by a compact parenthetical of specifics. Zero waste, every word earns its place. The structure is ideal for fast agent scanning.

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?

For a simple read-only, idempotent, non-destructive inventory tool with one optional parameter, the description is largely sufficient. The absence of an output schema means the description is the only return-format signal, and 'metric catalog plus thresholds' gives a reasonable sense of the payload. The main gap is the lack of differentiation from cgm_capabilities/cgm_agent_manifest, which slightly weakens completeness for tool-selection purposes.

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 description coverage is 100% — the single optional parameter privacy_mode is fully documented in the schema, including its enum values and what each mode omits (summary omits identifiers; structured/raw return full payload). The description adds no parameter detail, so the baseline 3 applies since the schema carries the semantic burden.

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 uses a specific verb ('Returns') and names a concrete resource ('metric catalog') plus its contents (thresholds, TIR ranges, GMI formula reference). This is clear about what the tool delivers. However, it does not distinguish itself from siblings like cgm_capabilities or cgm_agent_manifest, which could plausibly return overlapping catalog-like data, so the differentiation burden is unmet.

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?

No guidance is given on when to use this tool versus any of the 18 siblings. There are no exclusions, no when-not-to-use hints, and no mention of which sibling handles cases this tool does not (e.g., cgm_capabilities or cgm_agent_manifest). An agent has no stated basis to choose this over an alternative.

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