Get database read-cost

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

Annotations already declare readOnlyHint=true. The description adds context beyond annotations, explaining per-user attribution via Crossdeck and SDK identity, and lists the return structure (totals and breakdown). No contradictions.

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 three sentences, front-loading the main purpose. It is efficient without being overly verbose, but could be slightly more concise by removing the redundant statement about returns.

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 no output schema, the description adequately explains what is returned (per-user vs overhead totals and by-operation breakdown). Parameter documentation is complete in schema. The description is sufficient for the tool's moderate complexity.

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%, so baseline is 3. The description does not add significant extra meaning beyond the schema; it mentions 'last `days` days' but doesn't elaborate on the project parameter or provide additional constraints.

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 it gets an app's database read-cost over a period, split into per-user reads vs overhead, and breakdown by operation. It uses specific verb 'Get' and resource 'database read-cost', and distinguishes from siblings like get_revenue or get_error_affected_users.

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 use cases: 'what's driving our database reads' or 'which operation costs the most'. It does not explicitly state when not to use or compare to alternatives, but the context is clear enough for an agent to decide.

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