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

Annotations already cover the safety profile (readOnlyHint, openWorldHint=false), and the description adds real behavioral context: an implicit default period and an instruction to invoke immediately rather than asking a clarifying question. It also implicitly describes the returned content (attached vs missing). It does not state pagination or any rate/limit behavior, so it stops short of a 5.

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 purpose and default-period directive are front-loaded, and the example phrasings are short and each earns its place by covering a distinct user phrasing. No filler sentences.

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?

One optional enum parameter, no output schema, and no nested structures — the description specifies purpose, invocation default, and the shape of the answer (attached vs missing). Nothing an agent needs to call this correctly is absent.

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% and the single param is a self-explanatory enum, so the baseline is 3. The description adds value beyond the schema by endorsing current_quarter as the operative default and telling the agent not to solicit the period from the user, which is meaning the schema does not convey.

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+resource: reports which expenses have receipts attached and which are missing, scoped to a period. It clearly separates itself from the adjacent expense-query siblings by focusing on receipt completeness, though it never names those siblings explicitly.

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?

Explicitly routes the agent: 'Use for ANY question about receipts' with three concrete example phrasings that map to likely user intents. It also gives a decisive default ('call it straight away with the current quarter unless the user named another period — do not ask which period first'), removing ambiguity about both when to use it and how to open the call.

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