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

Annotations only supply readOnlyHint=false, so the description carries the burden and does it well: it discloses the null-clears semantics for defaultPaymentType, the opening-balance side effect of currentBalance, the mutual exclusion rule, category-move restrictions, and the required finance:write scope. These are non-obvious side effects an agent could not infer from the schema.

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-loads the field list, then layers constraints and finally the scope requirement, so all the high-value information is early. It is dense and reads as one long run-on string, but every clause carries a real constraint; only the trailing scope sentence could be repositioned.

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 12-parameter mutation tool with no annotations beyond readOnlyHint=false and no output schema, the description covers most of what is needed to call it correctly, including side effects and permissions. It leaves unstated whether unspecified fields are left unchanged (partial update semantics) and what the response contains.

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?

With only 8% schema description coverage across 12 parameters, the description compensates by explaining semantics the schema cannot express: null clears defaultPaymentType, currentBalance vs initialBalance interaction on system accounts, decimal amounts, and grouping the four logo* fields under 'logo'. Minor gap: the individual logo sub-fields (logoIcon/logoColor/logoDomain/logoInitials) and their null behavior go unmentioned.

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?

Opens with a specific verb+resource and enumerates the mutable fields (name, accountCategory, defaultPaymentType, creditLimit, excludeFromStats, logo, balances), so the agent knows exactly what surface this tool touches. It also explicitly distinguishes itself from archive_account, which is a plausible sibling for the same resource.

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?

Explicitly excludes archiving and routes to archive_account, and gives conditional rules (currentBalance only on manual accounts, initialBalance and currentBalance mutually exclusive, no moves into/out of vehicle or into loan). However, it never routes balance changes to the sibling adjust_account_balance, which is the other obvious alternative for the balance-related behavior it describes.

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