sw_attach_receipt

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

Annotations already flag destructiveHint=true and idempotentHint=true; the description adds real value on top by disclosing that an existing receipt is replaced, that no other expense fields are mutated, the failure mode, and the full confirmation/preview/confirmToken flow including the MCP_CONFIRM_MODE behavior. Nothing here contradicts the annotations.

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?

Front-loaded with purpose and the destructive/replace behavior, then the confirmation mechanics. Four dense sentences with little waste, though the confirmation detail makes it longer than strictly necessary.

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 nested-object mutation tool with no output schema, the description covers the destructive replace, the failure condition, and the confirm flow well. It stops short of saying what a successful call returns, which is a minor gap given there is no output schema.

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 all three parameters (including the nested receipt object and confirmToken) are already documented in the schema. The description reinforces 'Pass the file as receipt.base64' but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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 and resource ('Attach (or replace) the receipt image or PDF on an existing Splitwise expense') and immediately scopes what is NOT touched ('cost, split and description are not sent'). This clearly separates it from siblings like sw_get_receipt.

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?

Gives clear operating context: pass the file as receipt.base64, and it fails if Splitwise does not store the file. It explains the confirmation requirement and the two-step fallback, but names no explicit alternative tool or a 'do not use when' exclusion beyond the failure note.

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