list_dimensions

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

Annotations already provide readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds no additional behavioral context beyond the obvious 'returns a list.' It does not mention pagination behavior or any side effects, but given the annotations, the description is acceptable.

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 concise—only two sentences—and front-loaded with the core purpose. Every sentence adds value: first tells what it does, second tells when not to use it and alternatives. 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?

Given the tool has 2 params, no output schema, and good annotations, the description explains the purpose and usage clearly. It lacks detail on return format or pagination, but the schema covers parameters. Overall, it is sufficient for an agent to use correctly.

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 coverage is 100%, so baseline is 3. The description does not add any additional meaning to the parameters (filter and pageToken) beyond what the schema already provides. No extra context or format details are given.

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 'Returns a list of dimension types and values that can be used with run_query,' using a specific verb ('list' implied) and resource ('dimensions'). It distinguishes from siblings by explicitly stating when not to use it and naming alternatives (run_query, list_allocations).

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 explicitly says 'Use this when the user wants to see available dimensions for cost analysis queries.' It also provides explicit exclusions: 'Do NOT use this for running cost queries directly (use run_query) or viewing allocations (use list_allocations).' This gives clear when-to-use and when-not-to-use guidance.

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