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

With no annotations, the description carries full responsibility for behavioral disclosure. It implies a read operation ('Get') but does not state whether it is read-only, what computations are performed, or what the return structure looks like. No mention of side effects or data refresh behavior.

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 a single concise sentence, front-loaded with the action and resource. Every word serves a purpose, with no filler or redundant detail.

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 tool with one optional parameter, the description provides the core purpose but lacks detail on return format, scope, and edge cases. No output schema exists, so the description should clarify what 'summary and totals' means concretely. It is adequate but not rich.

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 schema defines one optional parameter 'period' with clear enum values (week/month/year/all). The description's 'by period' aligns with this but does not explain the enum semantics. Since the schema is self-explanatory, the description adds marginal value beyond confirming the parameter's role.

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 gets expense summary and totals by period. It uses a specific verb 'get' and resource 'expense summary/totals', which distinguishes it from write operations like log_expense. However, it doesn't explicitly differentiate from other getter tools that might also involve financial data.

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 provided on when to use this tool versus alternatives. There is no mention of exclusions, prerequisites, or comparison to similar getter tools. The only implicit hint is the period parameter, which suggests usage for period-based queries.

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