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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered. The description adds the behavioral concept that the result measures deviation from a one-year baseline, but it does not say how the comparison is expressed or what constitutes an 'unusual' threshold. Reasonable given annotations, but not rich.

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 well-formed sentence with the core comparison front-loaded and the use case in parentheses at the end. No filler, though it stays terse enough that it could afford one clarifying clause without becoming bloated.

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 single-parameter read tool with a 100%-covered schema and an output schema that carries the return values, the description covers what is needed to call it. The only real gap is ambiguity around what 'average daily range' means (high-low range vs. average absolute change), which an agent might misread.

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?

Only one parameter (symbolExchange) and schema coverage is 100%, with an example supplied in the schema itself, so the baseline is 3. The description adds no format or interpretation guidance about the symbol/exchange argument beyond what the schema already states.

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 verb (Compare) and specific resources (today's price change, average daily range over the last year) and even tags the analytical intent as 'unusual move detection'. It is far more specific than most siblings, but it never distinguishes itself from related tools like prices or market_lastday, so an agent still has to infer which one applies.

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 when-to-use or when-not-to-use guidance and no named alternative among the many sibling tools. The parenthetical '(unusual move detection)' implies the scenario the tool serves, which is enough to count as implied usage, but nothing tells the agent when this beats a plain prices lookup.

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