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

Annotations declare the safety profile (non-read-only, open-world, non-idempotent, non-destructive), and the description adds genuinely new behavioral context: this is a two-step out-of-band OAuth flow requiring user browser action, and successful authorization automatically persists the account. That side effect and human-in-the-loop requirement are not derivable from the annotations alone.

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?

Three short sentences, front-loaded with the core action and immediately followed by the required user step and the verification step. No filler or redundancy.

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, no-output-schema tool, the description covers the action, the out-of-band user step, the persistence side effect, and the next step. It implies the return value (an authorization URL) without needing a schema, though it does not say what happens on failure or how long the URL remains valid.

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 both parameters (label, environment) are already documented with defaults and enum meanings in the schema. The description adds no parameter-level detail such as how label is used or environment implications beyond what the schema states. Baseline 3 applies.

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+resource: "Generate an authorization URL to connect a cTrader broker account." An agent can distinguish this from data-fetching siblings, and it names test_broker_account as the follow-up. It does not, however, differentiate itself from the similarly named create_broker_account, leaving that inference to the caller.

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?

Gives clear usage context: the user must open the returned URL in a browser and authorize, after which the account is saved. It also names the verification follow-up (test_broker_account). No explicit when-not or alternative tool (e.g. create_broker_account) is given, so it stops short of a 5.

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