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

Annotations already declare this is not read-only, is idempotent, and is destructive. The description usefully adds partial-update semantics, but it does not explain what makes the operation destructive or mention permission/auth considerations.

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 a single front-loaded sentence with no wasted text. Both clauses carry useful information: the operation target and the partial-update behavior.

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 rich schema, annotations, and output schema, the description is mostly complete enough to invoke the tool correctly. Its main remaining gap is not stating when to prefer this over sibling update/create tools, but the structured fields already cover parameters and return values.

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 seven parameters are already documented in the schema. The description adds no per-parameter meaning beyond the general note that only passed fields change, so the baseline score 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 states a specific verb and resource: it changes an existing income or expense record. It also adds the key partial-update qualifier that only supplied fields are modified, making it clearly distinct from create/delete/get/list record operations.

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?

It implies use for modifying an existing record but gives no explicit when-to-use guidance, prerequisites, or comparison to alternatives such as create_record or update_recurring_expense. The agent must infer usage from the tool name and purpose alone.

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