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

Annotations already declare non-destructive, idempotent, open-world mutation, so the bar is lower. The description does add useful context beyond them: the partial-update guarantee ("Only maxJobs changes") and the return value ("Returns the stored account"), but it omits permission requirements, error behavior for out-of-range values, and what happens to concurrent jobs when the limit is lowered.

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-loaded with the effect and bounded range, then scope limits, then return value — a sensible order with no filler sentences. The trailing "POST /accounts." is a mild restatement that duplicates the earlier mention of POST /accounts and could be trimmed.

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 two-parameter mutation with no output schema, the description covers the effect, the range, the exclusivity of the change, and the return shape. It does not address authentication or what the agent should report back on failure, which keeps it short of fully complete.

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%, so baseline is 3, and the description earns an extra point by explaining that maxJobs counts requests where each request is 2 songs, a nuance the schema's "Requests at once, 1-4" does not convey. The remaining parameter (email) adds nothing beyond the schema but needs nothing.

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 in plain language ("Change how many song requests (2 songs each) an account runs at once, 1-4") and immediately narrows the scope with "Only maxJobs changes." An agent can tell this apart from account creation or password changes, which the description explicitly routes elsewhere.

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 says what this tool does NOT do ("adding an account or a new password goes through POST /accounts with email and password"), which is real when-not guidance. It lacks an explicit pointer to a named sibling tool and gives no prerequisite/authorization context, so it falls short of a full 5.

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