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

readOnlyHint=true already tells the agent this is a safe read with no side effects, so the description carries a lighter burden. It adds the resource scope and endpoint but says nothing about failure behavior (e.g., invalid or missing id) or the shape of the returned account.

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?

Two short, front-loaded fragments with no filler; the identifying purpose comes first. The trailing endpoint path is marginally useful for tracing but not strictly necessary for invocation.

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 one-parameter read tool this is minimally sufficient, and annotations cover the safety profile. However, with no output schema, the description could describe what an account record contains or how a missing id behaves, which would materially help an agent interpret the result.

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 100% and the id property is already documented with a useful caveat ('not the account number'), so the schema does the heavy lifting. The description adds nothing beyond restating that lookup is by id, which matches the baseline 3 for high-coverage schemas.

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?

States a specific verb and resource ('One account of the chart of accounts by id') plus the underlying endpoint, so the agent knows it retrieves a single account record. It is distinguishable from cashctrl_list_accounts and cashctrl_get_account_balance by the singular scope, though it never names those siblings explicitly.

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?

There is no when-to-use or when-not-to-use guidance; the only hint is 'by id', implying it is for lookup when an identifier is already known. No alternative is named for fetching multiple accounts (list_accounts) or balance data (get_account_balance).

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