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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation nature is known. The description adds valuable context: it lists mutable fields, states immutability of amount/date, and explains the 'excluded' flag's semantics (though the schema also covers that). It also implies 'learn_category' affects future behavior, but doesn't detail. Overall, description adds context beyond minimal 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?

The description is two sentences, the first front-loads the primary purpose and the second succinctly states the immutability constraint. No wasted words; every phrase adds information.

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 the tool is complex with 7 parameters, no output schema details needed as output schema exists. The description covers mutable fields, immutability, and the excluded semantics. It doesn't explicitly mention idempotency or error conditions, but with annotations covering destructive behavior and schema covering parameter details, it is mostly complete. A slight gap is not noting the effect of 'learn_category' on future parsing, but schema description covers it.

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 only 29%, so the description must compensate. It does explain the core fields (category, merchant, note, reviewed, excluded) and the immutability of amount/date. It also clarifies 'excluded' behavior. However, it does not explain 'learn_category' (though schema has a description) or 'category_id' format, but for commonly understood fields, this is sufficient.

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 updates a transaction's mutable fields (category, merchant, note, reviewed flag, excluded), and explicitly declares what is immutable (amount, date). It uses a specific verb and resource, and the list of fields distinguishes it from sibling tools like correct_transaction and delete_transaction.

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 implies it is for editing transaction details but does not explicitly state when to use it versus siblings like correct_transaction (which likely corrects amount/date) or delete_transaction. It mentions immutability of amount/date, hinting that correct_transaction may be needed for those, but this is not explicit.

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