get_available_size

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds only the 'currently' qualifier, suggesting a time-sensitive/current value, but does not explain data source, return behavior, or open-world characteristics beyond the annotation. No contradiction.

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?

The description is a single, direct sentence with no fluff or repetition. It is efficient, though its brevity comes at the cost of parameter and usage detail.

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?

No output schema exists, and the description does not specify the return value's format or the meaning of 'available size' (e.g., holdings-based vs market liquidity). It also omits how exchange affects the result, leaving the agent to guess. Given the low schema coverage and missing annotations context, this is insufficient.

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 0%, and the description does not explain the isin or exchange parameters; it never mentions them by name or role. 'Instrument' is the only implicit link to isin, and exchange's optional/null semantics are entirely unaddressed.

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 clearly frames the tool as a quantity query: 'How many units of an instrument can currently be sold.' It identifies a concrete resource (an instrument's sellable units) and is distinguishable from sibling tools such as get_quote or get_portfolio, though it does not explicitly carve out a sibling.

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?

There is no explicit guidance about when to choose this over get_quote/get_portfolio or place_order. The phrasing implies it should be used when the agent needs a current sellable quantity, but no alternatives, prerequisites, or when-not-to-use conditions are provided.

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