slippage

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

With no annotations, the description carries full behavioral burden but discloses only that the book is 'stored' — hinting at a local/cached read rather than a live fetch. It does not say whether the call is read-only, what happens when the stored book is empty or stale, or whether an error or null is returned for an unknown symbol.

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 zero filler, and the part that matters (what is computed) comes first. It is efficient but so compressed that it reads more like a title than a definition.

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 five-parameter analytics tool with no annotations and no output schema, the description omits both the return shape (price plus slippage in what units?) and any guidance on book staleness or asset-class selection. An agent could invoke it but would not know how to read the result relative to its siblings.

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 20% (only asset_class is documented in properties), so the description needed to compensate and does not — symbol, side, size, and size_unit are untouched. The phrase 'for a size' gestures at the size parameter but adds no unit, sign, or format semantics beyond the schema's anyOf.

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 computation (expected execution price and slippage) over a specific input (a size) against a specific source (the stored book), which is far more informative than the bare name. It stops short of distinguishing itself from the close sibling simulate-price-impact, so an agent cannot tell from the text alone which of the two to call.

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 when-to-use, no when-not-to-use, and no named alternative among the many siblings (simulate-price-impact, depth, liquidity-depth) that plausibly overlap. The agent must infer the division of labor entirely from tool names.

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