symbol_info

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds value by enumerating what comes back (record, latest tick, weekday sessions), but says nothing about staleness of the 'latest tick', error behavior for unknown symbols, or whether sessions are exchange-local.

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?

A single front-loaded sentence with no filler, and the return payloads are listed in a sensible order. It is efficient, though the terseness is partly what leaves the parameter and usage gaps.

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 with annotations covering safety and no output schema, the description does the minimum by describing return content. Completeness falls short on the symbol format and on the meaning of 'weekday sessions', which an agent cannot resolve from any structured field.

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?

There is one required parameter with 0% schema description coverage, so the description carries the burden of explaining it and does not. It never states the expected symbol format (e.g., 'EURUSD' vs 'EUR/USD' vs broker-specific naming) or whether it must come from list_symbols, which is a real risk for a lookup tool.

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?

Uses a specific verb ('Return') and names three concrete payloads: the full symbol_info record, the latest tick, and weekday sessions. That is clear enough to distinguish it from list_symbols (enumeration) and symbol_tick (tick only), though the overlap with symbol_tick is not explicitly resolved.

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 description gives no when-to-use guidance and never names the obvious alternatives in the sibling list, such as symbol_tick or list_symbols. An agent must infer from the payload list whether this is the right call for a metadata lookup versus a price lookup.

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