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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds real domain context: the `ready` state gate for trading and the warning that the login must not be used as an identifier elsewhere. It does not mention pagination limits or the practical size of a workspace's account list, but what it does add is behaviorally useful.

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 tight clauses: what is returned, how to reference an account, and the state caveat, followed by a minimal example. Every sentence earns its place and the field list is front-loaded. The trailing example is slightly redundant given the fully documented schema, which keeps it from a 5.

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?

An output schema exists, so return-value documentation is not the description's burden, and the description nonetheless previews the key fields an agent will need. With annotations covering safety, a complete schema, and the `ready`-state caveat plus the id-vs-login rule supplied, nothing required to call this tool correctly is missing.

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% and all three parameters carry their own descriptions (range, default, cursor provenance, response_format enum), so the schema does the heavy lifting and a 3 baseline applies. The inline example {"limit": 25} illustrates the call but adds no semantics beyond the documented default of 25. No parameter meaning is clarified further in prose.

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 names the resource (the workspace's MT5 accounts) and enumerates the identifying fields returned (id, login, server, state, environment), so an agent knows exactly what this call yields. The explicit 'use the id, not the login, everywhere else' rule also draws a clean boundary against get_account-style lookups. It never uses the verb 'list' outright, but the noun phrase plus the title make the read-all intent unambiguous.

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?

Usage is implied rather than stated: the agent learns that only `ready` accounts trade and that others must be brought online first, which gestures at bring_accounts_online without naming it. There is no explicit comparison against get_account, get_account_status or get_account_overview, so the agent must infer when listing beats fetching one account. Adequate but with a clear gap on exclusions and named alternatives.

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