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

The description discloses key behavioral traits beyond any annotations: it's a static catalog (reads no telemetry), returns the same answer for every caller, and is available to any authenticated user. Since no annotations are provided, the description fully covers the behavioral burden.

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?

The description is well-structured and front-loaded with the core purpose. The extra guidance about the alternative tool and usage order is provided in a separate sentence, making it easy to scan. No wasted words.

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 tool with zero parameters and no output schema, the description is exceptionally complete. It explains what the tool returns, its behavior (static), its access level, and how it relates to sibling tools. No gaps remain.

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 input schema has zero parameters and the schema description coverage is 100%, so there is nothing for the description to add about parameters. The description explains why no parameters are needed and provides all necessary context about what the tool returns.

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 clearly states the tool returns the static measure catalog for authoring alert rules, per source (LOGS, SPANS, METRICS), including measure functions, units, and defaultMode. It distinguishes itself from siblings like describe_schema and query's describe_schema by explicitly stating it no longer returns tenant services, groupable fields, or metric names.

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?

The description provides explicit guidance: call query's describe_schema first to get tenant services, groupable fields, and metric names, then use this tool only to pick a measure once you know the source and, for METRICS, the metric's kind. This clearly tells when to use it versus alternatives.

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