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

The annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false. The description adds useful behavioral context beyond those annotations: the API's default U.S. listing preference, how to request a specific listing including Canadian securities, and that upstream 404 and 409 responses are preserved. There is no contradiction with the annotations.

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 four short sentences, front-loads the core action, and every sentence adds distinct value: purpose, default behavior, alternative tool, and error behavior. There is no redundant or filler text.

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 six-parameter resolve tool with no output schema and no parameter descriptions, the description covers purpose, default routing, alternative tool selection, and error preservation. However, it leaves several parameters undocumented, so an agent may have to guess at the meaning of cs_only, details, and prefer_exchange.

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%, so the description must compensate for six undocumented parameters. It explains the intended use of exchange and symbol_exchange and the default U.S. preference, but it does not describe symbol, cs_only, details, or prefer_exchange, leaving most parameters semantically opaque.

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 states a specific verb and resource: 'Resolve a Stock Trends instrument identifier.' It also explicitly distinguishes this tool from the sibling lookup tool by saying 'Use lookup to explore alternatives,' so an agent can tell the two apart without opening either schema.

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?

It gives clear context for specifying 'exchange or canonical symbol_exchange' to target a particular listing, including Canadian securities, and names the lookup tool as the alternative for exploring options. It does not state when not to use this tool or which parameters are required, but the primary routing guidance is strong.

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