Update / recategorise a cash transaction

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

Annotations indicate write operation (readOnlyHint=false) and potentially destructive (destructiveHint=true). Description adds important behavioral context: it is a 'plain field edit' that does not affect settlement linkage or match status, and is blocked if the financial year is locked. This goes beyond what annotations provide.

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?

Four sentences, front-loaded with purpose, well-structured with clear exclusions and conditions. Every sentence adds value without redundancy.

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 11 parameters, no output schema, and annotations, the description covers essential behavioral aspects, prerequisites, restrictions, and limitations. It is complete enough for an agent to understand how and when to use this tool.

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 covers 82% of parameters with descriptions. Description adds value by highlighting the most important parameter (category) with examples and listing other editable fields (description, reference, posted date, amount). However, not all parameters are explicitly mentioned in the description, so schema does most of the work.

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?

Clearly states 'Edit an existing cash-ledger row' and lists specific editable fields. Distinguishes from sibling tools by explicitly stating what it does not do (change settlement linkage/match status) and pointing to alternatives (attribute_cash_transaction/detach_cash_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?

Provides explicit when-to-use context (editing category, description, etc.), what it does not do (settlement linkage), and alternatives. Includes prerequisite: find the row via list_cash_transactions. Also mentions blocked condition for locked financial year.

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