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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so safety profile is provided. The description adds the required OAuth scope ('project_cost_snapshots:write'), which is useful auth context. However, it does not disclose idempotency implications, duplicate-date handling, or whether snapshots are immutable.

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 sentences, zero waste. The core purpose is front-loaded and the auth requirement follows immediately. Nothing is repeated or over-explained.

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 6-parameter mutation tool with no output schema and rich annotations, the description covers the essential purpose and a key prerequisite. It could go further by noting whether duplicate snapshots for the same project/date are allowed or what makes the record unique, but it is largely sufficient.

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 the schema already documents all six parameters. The description adds only a vague temporal hint ('at a point in time') that maps to snapshot_date but provides no format, constraint, or meaning beyond what the schema supplies.

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?

States a specific verb ('Record') and resource ('cost snapshot for a project') with a temporal qualifier ('at a point in time'). Clear, but it does not distinguish itself from sibling create_project_* tools or explain how a cost snapshot differs from other project records.

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 gives no when-to-use guidance, no when-not-to-use conditions, and no alternatives. The only sentence beyond the purpose is a scope requirement, which is a prerequisite rather than usage context.

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