Update a memorandum entry

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

The description discloses a non-obvious destructive behavior: 'All lines are replaced with the newly provided lines', which is valuable beyond annotations. It also states the balancing constraint. Annotations declare idempotentHint=true and destructiveHint=false, and the description does not contradict them; it adds practical behavioral detail.

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 opening sentence 'Update a memorandum entry.' duplicates the title and adds no value. The remaining sentences are informative and the HTTP endpoint is useful, but the redundancy and lack of clear front-loading of the most critical warning (full line replacement) prevent a higher score.

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 update operation with no output schema, the description covers the essential semantics: update existing, replace lines, enforce balancing. It does not mention response details or permissions, but the schema and annotations cover the main constraints, so the agent has sufficient context to call it correctly.

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 input schema already provides rich descriptions for all parameters, including date format, line requirements, and the equal-total constraint. The description repeats the balancing condition but does not add meaning beyond the schema. With 67% schema coverage, a baseline of 3 is appropriate.

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 operation: 'Update an existing memorandum journal entry.' It also specifies key behavior (all lines replaced, debit/credit totals must be equal) and the HTTP endpoint, making it easy to distinguish from create_memorandum_entry or get_memorandum_entry.

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 this tool is for modifying an existing entry ('Update an existing...'), so an agent can infer it is not for creation or retrieval. However, it does not explicitly mention when to prefer this over create_memorandum_entry or provide exclusion criteria, leaving usage context only implied.

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