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

Annotations already declare readOnly=true, idempotent=true, destructive=false, openWorld=false, so the safety profile is covered. The description adds genuinely new behavioral context with 'last-read' balance, equity and free margin, warning the agent that these figures are cached rather than live — information not present in any structured field.

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 compact sentences with no waste: the field list leads, the example follows. Front-loaded and appropriately sized for a single-record getter.

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 required, and annotations carry the safety profile. What remains missing is routing information — nothing tells the agent why to pick get_account over get_account_overview, get_account_status, or get_account_figures, which is the main ambiguity for this dense sibling set.

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 the schema already documents account_id (including the 'not the MT5 login number' warning) and response_format's concise/detailed semantics. The description's example adds only marginal value beyond that documented baseline.

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 resource ('one account') and enumerates the key fields returned (login, broker, state, environment, balance, equity, free margin), which clearly implies single-record retrieval versus list_accounts. However it never distinguishes itself from the many similar siblings (get_account_overview, get_account_status, get_account_figures), so the agent must guess which 'get account' variant is right.

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?

The only usage cue is the example embedding '<id from list_accounts>', which implies a prerequisite ordering but is not stated as guidance. There is no when-to-use, when-not-to-use, or named alternative among get_account_overview / get_account_status / get_account_figures.

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